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Sannes JA, Gonano B, Fjellvåg ØS, Kumar S, Nilsen O, Valldor M. X-ray and Neutron Diffraction Studies of SrTe 2FeO 6Cl, an Oxide Chloride with Rare Anion Ordering. Inorg Chem 2023; 62:13081-13088. [PMID: 37531570 PMCID: PMC10428212 DOI: 10.1021/acs.inorgchem.3c01951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Indexed: 08/04/2023]
Abstract
The oxychloride SrTe2FeO6Cl is obtained by high-temperature solid-state synthesis under inert conditions in closed reaction vessels. The compound crystallizes in a novel monoclinic crystal structure that is described in the space group P121/n1 (No. 14). The unit cell parameters, a = 10.2604(1) Å, b = 5.34556(5) Å, c = 26.6851(3) Å, and β = 93.6853(4)°, and atomic parameters were determined from synchrotron diffraction data, starting from a model that was obtained from single-crystal X-ray diffraction data. The anion lattice exhibits a rare ordering of oxide and chloride ions: one-dimensional zig-zag ladders of chlorine (squarelike motif) are surrounded by an oxygen matrix. Two different iron sites coordinated solely to oxygen are present in the structure, one octahedral and one square pyramidal, both distorted. Similarly, two different strontium coordinations are present; the first homoleptic coordinated to eight oxygen atoms and the second heteroleptic coordinated to four oxygen and four chlorine atoms in a fac-like manner. The lone pair of Te(IV) is directed toward the larger chlorine atoms. Magnetic susceptibility measurements confirm that Fe is +3 (d5) in the high-spin electronic configuration, exhibiting an almost ideal spin-only moment, μeff = 5.65 μB Fe-1. The slightly negative Weiss constant (θCW = -39 K) suggests dominating antiparallel spin-to-spin coupling in the paramagnetic temperature range, agreeing with an observed long-range antiferromagnetic spin ordering below Néel temperature, TN ∼ 13 K, and a broad second order-like anomaly in the specific heat measurement data. Low-temperature neutron diffraction data reveal that the antiferromagnetic ordered phase is C-type, with a k-vector (1/2, 1/2, 0) and ordered moment of 4.14(7) μB. The spin structure can be described as antiferromagnetic ordered layers stacked along the a-axis, forming layers of squares that alternate along the c-axis.
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Affiliation(s)
- Johnny A. Sannes
- Centre
for Materials Science and Nanotechnology (SMN), Department of Chemistry, University of Oslo, Sem Sælands vei 26, Oslo N-0371, Norway
| | - Bruno Gonano
- Centre
for Materials Science and Nanotechnology (SMN), Department of Chemistry, University of Oslo, Sem Sælands vei 26, Oslo N-0371, Norway
| | - Øystein S. Fjellvåg
- Department
for Hydrogen Technology, Institute for Energy
Technology, Kjeller NO-2027, Norway
- Laboratory
for Neutron Scattering and Imaging, Paul
Scherrer Institute, Forschungsstrasse
111, Villigen PSI 5232, Switzerland
| | - Susmit Kumar
- Centre
for Materials Science and Nanotechnology (SMN), Department of Chemistry, University of Oslo, Sem Sælands vei 26, Oslo N-0371, Norway
| | - Ola Nilsen
- Centre
for Materials Science and Nanotechnology (SMN), Department of Chemistry, University of Oslo, Sem Sælands vei 26, Oslo N-0371, Norway
| | - Martin Valldor
- Centre
for Materials Science and Nanotechnology (SMN), Department of Chemistry, University of Oslo, Sem Sælands vei 26, Oslo N-0371, Norway
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2
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Frøen EH, Adler P, Valldor M. Synthesis and Properties of Ba 6Fe 2Te 3S 7, with an Fe Dimer in a Magnetic Singlet State. Inorg Chem 2023; 62:12548-12556. [PMID: 37487201 PMCID: PMC10410609 DOI: 10.1021/acs.inorgchem.3c01775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Indexed: 07/26/2023]
Abstract
A new quaternary sulfide telluride, Ba6Fe2Te3S7, was synthesized by a solid-state reaction, and its crystal structure is novel. X-ray diffraction data on powder and single crystals reveal an orthorhombic lattice with a = 9.7543(3) Å, b = 18.2766(6) Å, and c = 12.0549(4) Å, and the noncentrosymmetric space group Cmc21 (No. 36). The properties of the compound were studied by magnetic susceptibility investigations, specific heat measurements, Mössbauer spectroscopy, and density functional theory calculations. Assuming Ba2+ and, as verified by the Mössbauer spectra, Fe3+, the charge balance requires the presence of a polytelluride, suggested to be a straight-chain [Te34-] polyanion. Further, the crystal structure contains [Fe2S7]8- dimers of two vertex-sharing tetrahedra, with a nearly linear Fe-S-Fe atom arrangement. The dimer exhibits antiferromagnetic coupling, with a coupling constant J = -10.5 meV (H = -2JS1S2) and S = 5/2, resulting in a spin singlet ground state. The interdimer magnetic interaction is so weak that the magnetic dimers can be treated as individuals.
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Affiliation(s)
- Emil H. Frøen
- Centre
for Materials Science and Nanotechnology (SMN), Department of Chemistry, University of Oslo, Sem Sælands vei 26, NO-0371 Oslo, Norway
| | - Peter Adler
- Max-Planck-Institute
for Chemical Physics of Solids, Nöthnitzer Straße 40, DE-01187 Dresden, Germany
| | - Martin Valldor
- Centre
for Materials Science and Nanotechnology (SMN), Department of Chemistry, University of Oslo, Sem Sælands vei 26, NO-0371 Oslo, Norway
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Sannes J, Kizhake Malayil RK, Corredor LT, Wolter AUB, Grafe HJ, Valldor M. Synthesis and Characterization of Oxide Chloride Sr 2VO 3Cl, a Layered S = 1 Compound. ACS Omega 2023; 8:14233-14239. [PMID: 37091428 PMCID: PMC10116624 DOI: 10.1021/acsomega.3c01151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 03/24/2023] [Indexed: 05/03/2023]
Abstract
The mixed-anion compound with composition Sr2VO3Cl has been synthesized for the first time, using the conventional high-temperature solid-state synthesis technique in a closed silica ampule under inert conditions. This compound belongs to the known Sr2 TmO3Cl (Tm = Sc, Mn, Fe, Co, Ni) family, but with Tm = V. All homologues within this family can be described with the tetragonal space group P4/nmm (No. 129); from a Rietveld refinement of powder X-ray diffraction data on the Tm = V homologue, the unit cell parameters were determined to a = 3.95974(8) and c = 14.0660(4) Å, and the atomic parameters in the crystal structure could be estimated. The synthesized powder is black, implying that the compound is a semiconductor. The magnetic investigations suggest that Sr2VO3Cl is a paramagnet at high temperatures, exhibiting a μeff = 2.0 μB V-1 and antiferromagnetic (AFM) interactions between the magnetic vanadium spins (θCW = -50 K), in line with the V-O-V advantageous super-exchange paths in the V-O layers. Specific heat capacity studies indicate two small anomalies around 5 and 35 K, which however are not associated with long-range magnetic ordering. 35Cl ss-NMR investigations suggest a slow spin freezing below 4.2 K resulting in a glassy-like spin ground state.
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Affiliation(s)
- Johnny
A. Sannes
- Department
of Chemistry, University of Oslo, Sem Sælands vei 26, N-0371 Oslo, Norway
| | | | - Laura T. Corredor
- Leibniz
Institute for Solid State Research, IFW Dresden, Helmholtzstraβe 20, 01069 Dresden, Germany
| | - Anja U. B. Wolter
- Leibniz
Institute for Solid State Research, IFW Dresden, Helmholtzstraβe 20, 01069 Dresden, Germany
| | - Hans-Joachim Grafe
- Leibniz
Institute for Solid State Research, IFW Dresden, Helmholtzstraβe 20, 01069 Dresden, Germany
| | - Martin Valldor
- Department
of Chemistry, University of Oslo, Sem Sælands vei 26, N-0371 Oslo, Norway
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Nowak D, Valldor M, Rubrecht B, Froeschke S, Eltoukhy S, Büchner B, Hampel S, Gräßler N. Crystal growth of the 2D Janus rhodiumchalcohalide RhSeCl. Inorg Chem Front 2023. [DOI: 10.1039/d2qi02699f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The rapidly growing interest in synthesising 2D Janus materials is supported by the numerous theo- retical predictions of the unique properties of this material category. Here, we report the discovery...
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Wang G, Dorn KV, Siebeneichler S, Valldor M, Smetana V, Mudring AV. The missing link between zeolites and polyoxometalates. Sci Adv 2022; 8:eadd9320. [PMID: 36383662 PMCID: PMC9668284 DOI: 10.1126/sciadv.add9320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
Open framework materials such as zeolites and metalorganic frameworks are garnering tremendous interest because of their intriguing architecture and attractive functionalities. Thus, new types of open framework materials are highly sought after. Here, we present the discovery of completely new inorganic framework materials, where, in contrast to conventional inorganic open frameworks, the scaffold is not based on tetrahedral EO4 (E = main group element) but octahedral MO6 (M = transition metal) building blocks. These structural features place them closer to polyoxometalates than zeolites. The first representatives of this class of materials are [(R)24(NH4)14(PO(OH)2)6]·[M134(PO3(OH,F))96F120] (M = Co, R = C2Py = 1-ethylpyridinium and M = Ni, R = C4C1Py = 1-butyl-3-methylpyridinium) featuring interlinked fullerene-like nanosphere cavities. Having a transition metal building up the framework brings about interesting properties, for example, spin-glass behavior, and, with this particular topology, a hedgehog-like spin orientation.
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Affiliation(s)
- Guangmei Wang
- Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, Stockholm 10691, Sweden
| | - Katharina V. Dorn
- Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, Stockholm 10691, Sweden
| | - Stefanie Siebeneichler
- Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, Stockholm 10691, Sweden
| | - Martin Valldor
- Centre for Materials Science and Nanotechnology, Department of Chemistry, University of Oslo, Postbox 1033, Blindern, 0315 Oslo, Norway
| | - Volodymyr Smetana
- Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, Stockholm 10691, Sweden
| | - Anja-Verena Mudring
- Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, Stockholm 10691, Sweden
- Department of Chemistry and iNANO, 253 Aarhus University, 8000 Aarhus C, Denmark
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Siribbal SM, Ilyas S, Renner AM, Iqbal S, Muñoz Vázquez S, Moawia A, Valldor M, Hussain MS, Schomäcker K, Mathur S. Click functionalized biocompatible gadolinium oxide core-shell nanocarriers for imaging of breast cancer cells. RSC Adv 2022; 12:31830-31845. [PMID: 36380928 PMCID: PMC9641724 DOI: 10.1039/d2ra00347c] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 08/07/2022] [Indexed: 11/10/2022] Open
Abstract
Site-specific delivery using functionalized nanocarriers is in high demand in imaging applications of modern clinical research. To improve the imaging capabilities of conventionally used contrast agents and expand the targeting accuracy, functional gadolinium oxide based nanocarriers originated from homogeneous core shells structures (Gd2O3@SiO2@Fe3O4) were developed using a multilayer formation approach. The synthesis and chemical configuration for the covalent binding of macrocyclic chelating agents and estrogen targeting molecules on these nanocarriers were designed by a two-step chemical synthesis method. Initially, SiO2@Fe3O4 structures were prepared and encapsulated with a homogenous thin Gd2O3 overlayer. The exterior surface of the as-prepared carriers offered chemical binding with a breast cancer specific estrogen molecule, covalently grafted through a Click-Chemistry protocol. In the next step, to enhance the diagnostic imaging capabilities of these carriers, thiocyanate-linked chelator molecule, DOTA, was attached to the surface of estrogen bound Gd2O3@SiO2@Fe3O4 using basic reaction conditions. The active amino groups before and after conjugation of estrogen molecules on the surface were quantified using a fluorescamine based approach. Due to the covalent binding of the macrocyclic chelator to the Gd2O3@SiO2@Fe3O4 surface, core shell carriers showed potential radiolabeling efficiency using positron emitter radionuclide, gallium-68 (68Ga). Intracellular uptake of estrogen-conjugated carriers was evaluated with MCF7 breast cancer cell lines using confocal laser scanning microscopy and fluorescent flow cytometry. In addition, in vitro cytotoxicity studies of functional nanocarriers as compared to bare nanoparticles showed reduced toxicity to HEK-293 cells demonstrating the role of surface attached molecules in preventing direct exposure of the Gd2O3 surface to the cells. The as-developed gadolinium based nanocarriers presented excellent capabilities as biocompatible target-specific imaging probes which indicates great potential in the field of dual-mode contrast agents. Site-specific delivery using functionalized nanocarriers is in high demand in imaging applications of modern clinical research.![]()
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Affiliation(s)
- Shifaa M. Siribbal
- Institute of Inorganic Chemistry, University of Cologne, Greinstrasse 6, 50939 Cologne, Germany
| | - Shaista Ilyas
- Institute of Inorganic Chemistry, University of Cologne, Greinstrasse 6, 50939 Cologne, Germany
| | - Alexander M. Renner
- Institute of Inorganic Chemistry, University of Cologne, Greinstrasse 6, 50939 Cologne, Germany
| | - Sumiya Iqbal
- Institute of Inorganic Chemistry, University of Cologne, Greinstrasse 6, 50939 Cologne, Germany
| | - Sergio Muñoz Vázquez
- Clinic and Polyclinic for Nuclear Medicine, University of Cologne, Kerpenerstrasse 62, 50937 Cologne, Germany
| | - Abubakar Moawia
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, 50931 Cologne, Germany
- Center for Biochemistry, Medical Faculty, University of Cologne, 50931 Cologne, Germany
| | - Martin Valldor
- Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Strasse 40, 01187 Dresden, Germany
- Centre for Materials Science and Nanotechnology, Department of Chemistry, University of Oslo, Blindern, 0315 Oslo, Norway
| | - Muhammad S. Hussain
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, 50931 Cologne, Germany
- Center for Biochemistry, Medical Faculty, University of Cologne, 50931 Cologne, Germany
| | - Klaus Schomäcker
- Clinic and Polyclinic for Nuclear Medicine, University of Cologne, Kerpenerstrasse 62, 50937 Cologne, Germany
| | - Sanjay Mathur
- Institute of Inorganic Chemistry, University of Cologne, Greinstrasse 6, 50939 Cologne, Germany
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Stepanjuga A, Ray R, Richter M, Carrocci S, Hampel S, Galle L, Grafe HJ, Valldor M. Metathesis as alternative synthesis route to layered sulfides A(LiZn)S2 (A = alkali-metal) with unexpected colors. NEW J CHEM 2022. [DOI: 10.1039/d1nj05892d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Pure powders of Na(LiZn)S2 can be obtained through solid-state reaction, and A(LiZn)S2 (A = K, Rb, Cs) result from metathesis reactions between the alkali-metal chloride and the same constituents used...
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8
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Siribbal SM, Ilyas S, Renner AM, Iqbal S, Vázquez SM, Moawia A, Valldor M, Hussain MS, Schomäcker K, Mathur S. Correction: Click functionalized biocompatible gadolinium oxide core-shell nanocarriers for imaging of breast cancer cells. RSC Adv 2022; 12:34639. [DOI: 10.1039/d2ra90119f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 11/18/2022] [Indexed: 12/03/2022] Open
Abstract
Correction for ‘Click functionalized biocompatible gadolinium oxide core-shell nanocarriers for imaging of breast cancer cells’ by Shifaa M. Siribbal et al., RSC Adv., 2022, 12, 31830–31845, https://doi.org/10.1039/D2RA00347C.
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Affiliation(s)
- Shifaa M. Siribbal
- Institute of Inorganic Chemistry, University of Cologne, Greinstrasse 6, 50939 Cologne, Germany
| | - Shaista Ilyas
- Institute of Inorganic Chemistry, University of Cologne, Greinstrasse 6, 50939 Cologne, Germany
| | - Alexander M. Renner
- Institute of Inorganic Chemistry, University of Cologne, Greinstrasse 6, 50939 Cologne, Germany
| | - Sumiya Iqbal
- Institute of Inorganic Chemistry, University of Cologne, Greinstrasse 6, 50939 Cologne, Germany
| | - Sergio Muñoz Vázquez
- Clinic and Polyclinic for Nuclear Medicine, University of Cologne, Kerpenerstrasse 62, 50937 Cologne, Germany
| | - Abubakar Moawia
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, 50931 Cologne, Germany
- Center for Biochemistry, Medical Faculty, University of Cologne, 50931 Cologne, Germany
| | - Martin Valldor
- Max-Planck-Institut für Chemische Physik Fester Stoffe, Nöthnitzer Strasse 40, 01187 Dresden, Germany
- Centre for Materials Science and Nanotechnology, Department of Chemistry, University of Oslo, Blindern, 0315 Oslo, Norway
| | - Muhammad S. Hussain
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, 50931 Cologne, Germany
- Center for Biochemistry, Medical Faculty, University of Cologne, 50931 Cologne, Germany
| | - Klaus Schomäcker
- Clinic and Polyclinic for Nuclear Medicine, University of Cologne, Kerpenerstrasse 62, 50937 Cologne, Germany
| | - Sanjay Mathur
- Institute of Inorganic Chemistry, University of Cologne, Greinstrasse 6, 50939 Cologne, Germany
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Gorbunov MV, Carrocci S, Maletti S, Valldor M, Doert T, Hampel S, Gonzalez Martinez IG, Mikhailova D, Gräßler N. Synthesis of (Li 2Fe 1-yMn y)SO Antiperovskites with Comprehensive Investigations of (Li 2Fe 0.5Mn 0.5)SO as Cathode in Li-ion Batteries. Inorg Chem 2020; 59:15626-15635. [PMID: 33047957 DOI: 10.1021/acs.inorgchem.0c01753] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of solid solutions (Li2Fe1-yMny)SO with a cubic antiperovskite structure was successfully synthesized. The composition (Li2Fe0.5Mn0.5)SO was intensively studied as a cathode in Li-ion batteries showing a reversible specific capacity of 120 mA h g-1 and almost a 100% Coulombic efficiency after 50 cycles at 0.1C meaning extraction/insertion of 1 Li per formula unit during 10 h. Operando X-ray absorption spectroscopy confirmed the redox activity of both Fe2+ and Mn2+ cations during battery charge and discharge, while operando synchrotron X-ray diffraction studies revealed a reversible formation of a second isostructural phase upon Li-removal and insertion at least for the first several cycles. In comparison to (Li2Fe)SO, the presence of Mn stabilizes the crystal structure of (Li2Fe0.5Mn0.5)SO during battery operation, although post mortem TEM studies confirmed a gradual amorphization after 50 cycles. A lower specific capacity of (Li2Fe0.5Mn0.5)SO in comparison to (Li2Fe)SO is probably caused by slower kinetics, especially in the two-phase region, as confirmed by Li-diffusion coefficient measurements.
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Affiliation(s)
- Mikhail V Gorbunov
- Leibniz Institute for Solid State and Materials Research (IFW) Dresden e.V., Helmholtzstrasse 20, D-01069 Dresden, Germany
| | - Salvatore Carrocci
- Leibniz Institute for Solid State and Materials Research (IFW) Dresden e.V., Helmholtzstrasse 20, D-01069 Dresden, Germany
| | - Sebastian Maletti
- Leibniz Institute for Solid State and Materials Research (IFW) Dresden e.V., Helmholtzstrasse 20, D-01069 Dresden, Germany
| | - Martin Valldor
- Leibniz Institute for Solid State and Materials Research (IFW) Dresden e.V., Helmholtzstrasse 20, D-01069 Dresden, Germany.,Department of Chemistry, University of Oslo, Postbox 1033, Blindern, N - 0315 Oslo, Norway
| | - Thomas Doert
- Faculty of Chemistry and Food Chemistry, Technische Universität Dresden 01069 Dresden, Germany
| | - Silke Hampel
- Leibniz Institute for Solid State and Materials Research (IFW) Dresden e.V., Helmholtzstrasse 20, D-01069 Dresden, Germany
| | | | - Daria Mikhailova
- Leibniz Institute for Solid State and Materials Research (IFW) Dresden e.V., Helmholtzstrasse 20, D-01069 Dresden, Germany
| | - Nico Gräßler
- Leibniz Institute for Solid State and Materials Research (IFW) Dresden e.V., Helmholtzstrasse 20, D-01069 Dresden, Germany
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Siebeneichler S, Dorn KV, Smetana V, Valldor M, Mudring AV. A soft chemistry approach to the synthesis of single crystalline and highly pure (NH 4)CoF 3 for optical and magnetic investigations. J Chem Phys 2020; 153:104501. [PMID: 32933281 DOI: 10.1063/5.0023343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A new ionothermal synthesis utilizing 1-alkyl-pyridinium hexafluorophosphates [CxPy][PF6] (x = 2, 4, 6) led to the formation of highly crystalline single-phase ammonium cobalt trifluoride, (NH4)CoF3. Although ammonium transition-metal fluorides have been extensively studied with respect to their structural and magnetic properties, multiple aspects remain unclear. For that reason, the obtained (NH4)CoF3 has been investigated over a broad temperature range by means of single-crystal and powder x-ray diffraction as well as magnetization and specific heat measurements. In addition, energy-dispersive x-ray and vibrational spectroscopy as well as thermal analysis measurements were undertaken. (NH4)CoF3 crystallizes in the cubic perovskite structure and undergoes a structural distortion to a tetragonal phase at 127.7 K, which also is observable in the magnetic susceptibility measurements, which has not been observed before. A second magnetic phase transition occurring at 116.9 K is of second-order character. The bifurcation of the susceptibility curves indicates a canted antiferromagnetic ordering. At 2.5 K, susceptibility measurements point to a third phase change for (NH4)CoF3.
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Affiliation(s)
- Stefanie Siebeneichler
- Department of Materials and Environmental Chemistry (MMK), Stockholm University, Svante Arrhenius väg 16 C, 10691 Stockholm, Sweden
| | - Katharina V Dorn
- Department of Materials and Environmental Chemistry (MMK), Stockholm University, Svante Arrhenius väg 16 C, 10691 Stockholm, Sweden
| | - Volodymyr Smetana
- Department of Materials and Environmental Chemistry (MMK), Stockholm University, Svante Arrhenius väg 16 C, 10691 Stockholm, Sweden
| | - Martin Valldor
- Centre for Materials Science and Nanotechnology (SMN), Department of Chemistry, University of Oslo, Postbox 1033, Blindern 0315, Oslo, Norway
| | - Anja-Verena Mudring
- Department of Materials and Environmental Chemistry (MMK), Stockholm University, Svante Arrhenius väg 16 C, 10691 Stockholm, Sweden
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11
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Kim JK, Ranjith KM, Burkhardt U, Prots Y, Baenitz M, Valldor M. Impact of inversion symmetry on a quasi-1D S = 1 system. J Phys Condens Matter 2020; 32:225802. [PMID: 31997776 DOI: 10.1088/1361-648x/ab7134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Here, we report the synthesis and magnetic properties of a novel, centrosymmetric, quasi-1D spin chain system La3VWS3O6, with hexagonal crystal structure (P63/m, a = 9.460 76(3), c = 5.518 09(2) Å). Pure powders were obtained by solid-state reactions from La2O3, WO3 and metal powders of V and W. X-ray powder diffraction, specific heat, magnetization, 139La-nuclear magnetic resonance (NMR), and electric resistivity measurements indicate that the compound is a low dimensional magnet with an S = 1 spin chain that exhibits no sign of magnetic ordering above 2 K. A single ion anisotropy (D/k B ~ 10 K), caused by magneto-crystalline effects, is probably responsible for a thermodynamic entropy release at lower temperatures, which concurs with 139La-NMR data. By detailed comparison with non-centrosymmetric Ba3V2S4O3, having a very similar magnetic lattice, it is obvious that the presence of crystallographic inversion symmetry has an effect on the behaviour of the magnetic chains.
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Affiliation(s)
- J K Kim
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany. Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
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13
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Valldor M, Galle L, Eichler F, Wolf A, Morrow R. Synthesis, Crystal Structure, and Optical Characterization of the Sulfide Chloride Oxide CsBa 6V 4S 12ClO 4 with a Near-Infrared Fluorescence. Inorg Chem 2019; 58:14728-14733. [PMID: 31618005 DOI: 10.1021/acs.inorgchem.9b02393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
When CsCl, BaS, BaO, V, and S are reacted in a solid-state reaction under inert conditions, pure powders and single crystals of senary CsBa6V4S12ClO4 can be obtained. Its unique crystal structure has the symmetry R3̅H (no. 148) and unit cell parameters a = 9.0575(2) and c = 28.339(1) Å. The crystal structure contains polar units [VS3O]3- and a complex BaS7ClO2 coordination. The compound gets its deep-red color from a low-energy charge transfer, which can be explained by an electron transfer from S2- to V5+. In the near-infrared range, down-converted fluorescence occurs at 1.06 and 0.90 eV, and both emissions appear <450 ps after excitation at about 1.27 eV.
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Affiliation(s)
- Martin Valldor
- Leibniz Institute for Materials and Solid State Research IFW e.V. , Helmholtzstraße 20 , DE-01069 Dresden , Germany.,Centre for Materials Science and Nanotechnology (SMN), Department of Chemistry , University of Oslo , P.O. Box 1033 Blindern, N-0315 Oslo , Norway
| | - Lydia Galle
- Inorganic Chemistry , TU-Dresden , Bergstraße 66 , DE-01069 Dresden , Germany
| | - Franziska Eichler
- Physical Chemistry , TU-Dresden , Bergstraße 66b , DE-01069 Dresden , Germany
| | - André Wolf
- Physical Chemistry , TU-Dresden , Bergstraße 66b , DE-01069 Dresden , Germany
| | - Ryan Morrow
- Leibniz Institute for Materials and Solid State Research IFW e.V. , Helmholtzstraße 20 , DE-01069 Dresden , Germany
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14
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Wang G, Valldor M, Siebeneichler S, Wilk-Kozubek M, Smetana V, Mudring AV. Ionothermal Synthesis, Structures, and Magnetism of Three New Open Framework Iron Halide-Phosphates. Inorg Chem 2019; 58:13203-13212. [PMID: 31539232 DOI: 10.1021/acs.inorgchem.9b02028] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A set of different open framework iron phosphates have been synthesized ionothermally using a task-specific ionic liquid, 1-butyl-4-methylpyridinium hexafluorophosphate, that acts in the synthesis as the reaction medium and mineralizer: (NH4)2Fe2(HPO4)(PO4)Cl2F (1) and K2Fe2(HPO4)(PO4)Cl2F (2) exhibit similar composition and closely related structural features. Both structures consist of {Fe2(HPO4)(PO4)Cl2F}2- macroanions and charge balancing ammonium or potassium cations. Their open framework structure contains layers and chains of corner-linked {Fe(1)O2Cl4} and {Fe(2)F2O4} octahedra, respectively, interconnected by PO4 tetrahedra forming 10-ring channels. KFe(PO3F)F2 (3) is built up by {Fe[(PO3F)4/3F2/2]}{Fe(PO3F)2/3F2/2F2} layers separated by K+ cations. Chains of alternating {FeF2O4} and {FeO2F4} octahedra, which are linear for 1 but undulated for 2, are linked to each other via corner-sharing {PO3F} tetrahedra with the fluorine pointing into the interlayer space. The compounds were characterized by means of single crystal and powder X-ray diffraction, infrared spectroscopy, and magnetic measurements. 1 reveals a strong ground state spin anisotropy with a spin 5/2 state and a magnetic moment of 5.3 μB/Fe3+. Specific heat and magnetic data unveil three magnetic transitions at 95, 50, and 3.6 K. Compound 2 has a very similar crystal structure as compared to 1 but exhibits a different magnetic behavior: a slightly lower magnetic moment of 4.7 μB/Fe3+ and a magnetic transition to a canted antiferromagnetic state below 90 K. Compound 3 exhibits typical paramagnetic behavior close to room-temperature (5.71 μB/Fe3+). There are no clear indications for a phase transition down to 2 K despite strong antiferromagnetic spin-spin interactions; only a magnetic anomaly appears at 50 K in the zero-field cooled data.
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Affiliation(s)
- Guangmei Wang
- Fakultät für Chemie und Biochemie , Ruhr-Universität Bochum , Universitätsstraße 150 , D-44780 Bochum , Germany
| | - Martin Valldor
- Leibniz-Institute for Solid State and Materials Research Dresden , Helmholtzstraße 20 , 01069 Dresden , Germany
| | - Stefanie Siebeneichler
- Department of Materials and Environmental Chemistry , Stockholm University , Svante Arrhenius väg 16 C , 10691 Stockholm , Sweden
| | - Magdalena Wilk-Kozubek
- Department of Materials and Environmental Chemistry , Stockholm University , Svante Arrhenius väg 16 C , 10691 Stockholm , Sweden.,ŁUKASIEWICZ Research Network-PORT Polish Center for Technology Development , 147 Stabłowicka Street , 54-066 Wrocław , Poland
| | - Volodymyr Smetana
- Department of Materials and Environmental Chemistry , Stockholm University , Svante Arrhenius väg 16 C , 10691 Stockholm , Sweden
| | - Anja-Verena Mudring
- Fakultät für Chemie und Biochemie , Ruhr-Universität Bochum , Universitätsstraße 150 , D-44780 Bochum , Germany.,Department of Materials and Environmental Chemistry , Stockholm University , Svante Arrhenius väg 16 C , 10691 Stockholm , Sweden
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15
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Valldor M, Morrow R. Bichalcogenide Model Systems for Magnetic Chains with Variable Spin Sizes and Optional Crystallographic Inversion Symmetry. Inorg Chem 2019; 58:11978-11982. [PMID: 31247813 DOI: 10.1021/acs.inorgchem.9b00610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To develop an understanding of the magnetism on one-dimensional lattices, one of the great challenges is to identify novel model systems with enough chemical flexibility to design the magnetic interactions in measurable samples. To contribute to this endeavor, we present a number of bichalcogenides with similar trigonal packing of magnetic chains. These chains consist of 3d transition-metal (TM) ions that are 6-fold-coordinated by S or Se. Each TM coordination can be described as a trigonally distorted octahedron that shares faces with two neighboring octahedra. A unique ability with these model systems is that an entity with electric polarity can be introduced between the chains that causes the TM ions in the chains to shift to polar positions, thereby allowing for magnetoelectric coupling. By a comparison of the macroscopic data of polar and nonpolar chains with either S = 1 or S = 3/2, it is obvious that the magnetic properties are affected by the indirect electric polarity from the entity between the chains.
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Affiliation(s)
- Martin Valldor
- Leibniz Institute for Solid State and Materials Research , Helmholtzstraße 20 , DE-01069 Dresden , Germany
| | - Ryan Morrow
- Leibniz Institute for Solid State and Materials Research , Helmholtzstraße 20 , DE-01069 Dresden , Germany
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16
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Grönke M, Pohflepp D, Schmidt P, Valldor M, Oswald S, Wolf D, Hao Q, Steiner U, Büchner B, Hampel S. Simulation and synthesis of α-MoCl3 nanosheets on substrates by short time chemical vapor transport. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.nanoso.2019.100324] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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17
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Abstract
Novel bichalcogenides with the general composition (Li2TM)ChO (TM = Mn, Co; Ch = S, Se) were synthesized by single-step solid-state reactions. These compounds possess cubic anti-perovskite crystal structure with Pm3̅ m symmetry; TM and Li are disordered on the crystallographic site 3c. According to Goldschmidt tolerance factor calculations, the available space at the 3c site is too large for Li+ and TM2+ ions. As cathode materials, all title compounds perform less prominent in lithium-ion battery setups in comparison to the already known TM = Fe homologue; e.g., (Li2Co)SO has a charge density of about 70 mAh g-1 at a low charge rate. Nevertheless, the title compounds extend the chemical flexibility of the anti-perovskites, revealing their outstanding chemical optimization potential as lithium battery cathode material.
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Affiliation(s)
- Kwing To Lai
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40 , DE-01187 Dresden , Germany.,Department of Physics , The Chinese University of Hong Kong , Shatin , Hong Kong
| | - Iryna Antonyshyn
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40 , DE-01187 Dresden , Germany
| | - Yurii Prots
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40 , DE-01187 Dresden , Germany
| | - Martin Valldor
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40 , DE-01187 Dresden , Germany.,Leibniz Institute for Solid State and Materials Research , Helmholtzstraße 20 , DE-01069 Dresden , Germany
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18
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Grönke M, Schmidt P, Valldor M, Oswald S, Wolf D, Lubk A, Büchner B, Hampel S. Chemical vapor growth and delamination of α-RuCl 3 nanosheets down to the monolayer limit. Nanoscale 2018; 10:19014-19022. [PMID: 30265265 DOI: 10.1039/c8nr04667k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The 2D layered honeycomb magnet α-ruthenium(iii) chloride (α-RuCl3) is a promising candidate to realize a Kitaev spin model. As alteration of physical properties on the nanoscale is additionally intended, new synthesis approaches to obtain phase pure α-RuCl3 nanocrystals have been audited. Thermodynamic simulations of occurring gas phase equilibria were performed and optimization of synthesis conditions was achieved based on calculation results. Crystal growth succeeded via chemical vapor transport (CVT) in a temperature gradient of 973 K to 773 K on YSZ substrates. Single crystal sheets of high crystallinity with heights ≤30 nm were obtained via pure CVT. The crystal properties were characterized by means of optical and electron microscopy, AFM, SAED, micro-Raman and XPS proving their composition, morphology, crystallinity and phase-purity. A highlight of our study is the successful individualization of nanocrystals and the delamination of nanosheets on YSZ substrates down to the monolayer limit (≤1 nm) which was realized by means of substrate exfoliation and ultrasonication in a very reproducible way.
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Affiliation(s)
- Martin Grönke
- Leibniz-Institute for Solid State and Materials Research Dresden, Helmholtzstraße 20, 01069 Dresden, Germany.
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19
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Qureshi N, Fernández-Díaz MT, Chapon L, Senyshyn A, Schweika W, Valldor M. Complex magnetic structure of the swedenborgite CaBa(Co 3Fe)O 7 derived by unpolarized neutron diffraction and spherical neutron polarimetry. Acta Crystallogr A Found Adv 2018. [DOI: 10.1107/s2053273318093725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
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20
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Valldor M, Mikhailova D, Giebeler L, Lai KT, Spillecke L, Grafe HJ, Büchner B. Synthesis, Characterization, and Electrochemistry of Layered Chalcogenides LiCu Ch ( Ch = Se, Te). Inorg Chem 2018; 57:7201-7207. [PMID: 29808682 DOI: 10.1021/acs.inorgchem.8b00897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two novel compounds, LiCu Ch ( Ch = Se or Te), were synthesized by direct reaction between elements in closed ampules inside corundum crucibles. Both compounds are highly air-sensitive and possess an anti-PbClF crystal structure, which contains Cu Ch layer analogues to the Fe[As/Se] layers in Fe-based superconductors. In electrochemical battery cells, Li can be almost completely extracted from LiCuSe, but the reverse reaction is only partly successful and Li2Se and Cu2- xSe are formed instead. LiCuSe exhibits a temperature independent and slightly positive magnetic susceptibility. From 7Li NMR measurements, the activation energy of the Li ion diffusion process is about 0.5 eV but is slightly lower for LiCuTe as compared to LiCuSe. Also, the small and almost temperature independent NMR shifts of the 7Li nucleus indicate the absence of Pauli paramagnetism in these compounds, consistent with a 3 d10 full valence state of the Cu ions.
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Affiliation(s)
- Martin Valldor
- Leibniz Institute for Solid State and Materials Research (IFW) e.V. , Helmholtzstraße 20 , 01069 Dresden , Germany
| | - Daria Mikhailova
- Leibniz Institute for Solid State and Materials Research (IFW) e.V. , Helmholtzstraße 20 , 01069 Dresden , Germany
| | - Lars Giebeler
- Leibniz Institute for Solid State and Materials Research (IFW) e.V. , Helmholtzstraße 20 , 01069 Dresden , Germany
| | - Kwing To Lai
- Department of Physics , The Chinese University of Hong Kong , Shatin , Hong Kong
| | - Lena Spillecke
- Leibniz Institute for Solid State and Materials Research (IFW) e.V. , Helmholtzstraße 20 , 01069 Dresden , Germany
| | - Hans-Joachim Grafe
- Leibniz Institute for Solid State and Materials Research (IFW) e.V. , Helmholtzstraße 20 , 01069 Dresden , Germany
| | - Bernd Büchner
- Leibniz Institute for Solid State and Materials Research (IFW) e.V. , Helmholtzstraße 20 , 01069 Dresden , Germany
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21
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Valldor M, Yadav R, Hozoi L, van den Brink J, Maljuk A, Werner J, Scaravaggi F, Wolter AUB, Büchner B. Swedenborgite
CaBa(Mn
2
Fe
2
)O
7
with Spin Ordering on a Geometrically Frustrated, Polar, Non‐centrosymmetric
S
= 5/2 Lattice. Z Anorg Allg Chem 2017. [DOI: 10.1002/zaac.201700292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Martin Valldor
- Institute for Solid State Research Leibniz Institute for Solid State and Materials Research, Dresden Helmholtzstraße 20 01069 Dresden Germany
| | - Ravi Yadav
- Institute for Theoretical Solid State Physics Leibniz Institute for Solid State and Materials Research, Dresden Helmholtzstraße 20 01069 Dresden Germany
| | - Liviu Hozoi
- Institute for Theoretical Solid State Physics Leibniz Institute for Solid State and Materials Research, Dresden Helmholtzstraße 20 01069 Dresden Germany
| | - Jeroen van den Brink
- Institute for Theoretical Solid State Physics Leibniz Institute for Solid State and Materials Research, Dresden Helmholtzstraße 20 01069 Dresden Germany
| | - Andrey Maljuk
- Institute for Solid State Research Leibniz Institute for Solid State and Materials Research, Dresden Helmholtzstraße 20 01069 Dresden Germany
| | - Jochen Werner
- Institute for Solid State Research Leibniz Institute for Solid State and Materials Research, Dresden Helmholtzstraße 20 01069 Dresden Germany
| | - Francesco Scaravaggi
- Institute for Solid State Research Leibniz Institute for Solid State and Materials Research, Dresden Helmholtzstraße 20 01069 Dresden Germany
| | - Anja U. B. Wolter
- Institute for Solid State Research Leibniz Institute for Solid State and Materials Research, Dresden Helmholtzstraße 20 01069 Dresden Germany
| | - Bernd Büchner
- Institute for Solid State Research Leibniz Institute for Solid State and Materials Research, Dresden Helmholtzstraße 20 01069 Dresden Germany
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22
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Abstract
Small single crystals of Sr2Fe3Ch2O3 (Ch = S, Se) have been synthesized by flux methods, and bulk materials have been obtained by solid state reactions. Both compounds are isostructural to the compound Sr2Co3S2O3 (space group Pbam), which contains a novel hybrid spin ladder: a combination of a 2-leg rectangular ladder and a necklace ladder. The 2-leg ladder acts as a well-defined magnetic entity, while intimate magnetic coupling to the necklace ladder induces three successive phase transitions in the range of 40-120 K in each composition (Ch = S or Se), as revealed by Mössbauer spectroscopy, thermodynamics, and magnetometry. The complex magnetic behaviors can be explained by the unique spin-lattice topology.
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Affiliation(s)
- Kwing To Lai
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Strasse 40, 01187 Dresden, Germany.,Department of Physics, The Chinese University of Hong Kong , Shatin, Hong Kong
| | - Peter Adler
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Strasse 40, 01187 Dresden, Germany
| | - Yurii Prots
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Strasse 40, 01187 Dresden, Germany
| | - Zhiwei Hu
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Strasse 40, 01187 Dresden, Germany
| | - Chang-Yang Kuo
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Strasse 40, 01187 Dresden, Germany
| | - Tun-Wen Pi
- National Synchrotron Radiation Research Centre , Hsinchu 30076, Taiwan
| | - Martin Valldor
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Strasse 40, 01187 Dresden, Germany.,Leibniz Institute for Solid State and Materials Research , Helmholtz Strasse 20, 01069 Dresden, Germany
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23
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Krest A, Sandleben A, Valldor M, Werker M, Ruschewitz U, Klein A. Heteroleptic Complexes of the Tridentate Pyridine-2,6-di-tetrazolate Ligand. ChemistrySelect 2017. [DOI: 10.1002/slct.201701124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Alexander Krest
- Department für Chemie; Institut für Anorganische Chemie; Universität zu Köln; Greinstraße 6 D-50939 Köln Germany, Web
| | - Aaron Sandleben
- Department für Chemie; Institut für Anorganische Chemie; Universität zu Köln; Greinstraße 6 D-50939 Köln Germany, Web
| | - Martin Valldor
- Max Planck Institute for Chemical Physics of Solids; Nöthnitzer Straβe 40 01187 Dresden Germany
- Leibniz Institute for Solid State and Materials Research; Helmholtzstr. 20 01069 Dresden Germany
| | - Melanie Werker
- Department für Chemie; Institut für Anorganische Chemie; Universität zu Köln; Greinstraße 6 D-50939 Köln Germany, Web
| | - Uwe Ruschewitz
- Department für Chemie; Institut für Anorganische Chemie; Universität zu Köln; Greinstraße 6 D-50939 Köln Germany, Web
| | - Axel Klein
- Department für Chemie; Institut für Anorganische Chemie; Universität zu Köln; Greinstraße 6 D-50939 Köln Germany, Web
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24
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Affiliation(s)
- Kwing To Lai
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, DE-01187 Dresden, Germany
| | - Iryna Antonyshyn
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, DE-01187 Dresden, Germany
| | - Yurii Prots
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, DE-01187 Dresden, Germany
| | - Martin Valldor
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, DE-01187 Dresden, Germany
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25
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Lai KT, Komarek AC, Fernández-Díaz MT, Chang PS, Huh S, Rosner H, Kuo CY, Hu Z, Pi TW, Adler P, Ksenofontov V, Tjeng LH, Valldor M. Canted Antiferromagnetism on Rectangular Layers of Fe 2+ in Polymorphic CaFeSeO. Inorg Chem 2017; 56:4271-4279. [PMID: 28345884 DOI: 10.1021/acs.inorgchem.6b02098] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
From stoichiometric amounts of CaO, Fe, and Se, pure powders and single crystals of quaternary [Formula: see text] can be obtained by solid-state reaction and self-flux growth, respectively. The as-synthesized compound exhibits a polymorphic crystal structure, where the two modifications have different stacking sequences of [Formula: see text] layers. The two polymorphs have similar unit cells but different crystal symmetries (Cmc21 and Pnma), of which the former is non-centrosymmetric. Fe is divalent (d6) and high-spin, as proven by X-ray spectroscopy, Mössbauer spectroscopy, and powder neutron diffraction data. The latter two, in combination with magnetic susceptibility and specific heat data, reveal a long-range antiferromagnetic spin order (TN = 160 K) with a minor spin canting. CaFeSeO is an electronic insulator, as confirmed by resistivity measurements and density functional theory calculations. The latter also suggest a relatively small energy difference between the two polymorphs, explaining their intimate intergrowth.
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Affiliation(s)
- Kwing To Lai
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40, 01187 Dresden, Germany
| | | | | | - Pi-Shan Chang
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40, 01187 Dresden, Germany.,Department of Electrophysics, National Chiao Tung University , HsinChu 30100, Taiwan
| | - Sungjoon Huh
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40, 01187 Dresden, Germany.,University of British Colombia , 2329 West Mall, Vancouver, BC V6T 1Z4, Canada
| | - Helge Rosner
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Chang-Yang Kuo
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Zhiwei Hu
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Tun-Wen Pi
- National Synchrotron Radiation Research Centre , Hsinchu 30076, Taiwan
| | - Peter Adler
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Vadim Ksenofontov
- Institut für Anorganische und Analytische Chemie, Johannes Gutenberg-Universität , 55128 Mainz, Germany
| | - Liu Hao Tjeng
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Martin Valldor
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40, 01187 Dresden, Germany
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26
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Nemrava S, Vinnik DA, Hu Z, Valldor M, Kuo CY, Zherebtsov DA, Gudkova SA, Chen CT, Tjeng LH, Niewa R. Three Oxidation States of Manganese in the Barium Hexaferrite BaFe12–xMnxO19. Inorg Chem 2017; 56:3861-3866. [DOI: 10.1021/acs.inorgchem.6b02688] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | - Zhiwei Hu
- Max-Planck-Institute for Chemical Physics of Solids, Dresden 01187, Germany
| | - Martin Valldor
- Max-Planck-Institute for Chemical Physics of Solids, Dresden 01187, Germany
| | - Chang-Yang Kuo
- Max-Planck-Institute for Chemical Physics of Solids, Dresden 01187, Germany
| | | | - Svetlana A. Gudkova
- South Ural State University, Chelyabinsk 454080, Russia
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow Region 141700, Russia
| | - Chien-Te Chen
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Liu Hao Tjeng
- Max-Planck-Institute for Chemical Physics of Solids, Dresden 01187, Germany
| | - Rainer Niewa
- University of Stuttgart, Stuttgart 70049, Germany
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27
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Lai KT, Valldor M. Coexistence of spin ordering on ladders and spin dimer formation in a new-structure-type compound Sr 2Co 3S 2O 3. Sci Rep 2017; 7:43767. [PMID: 28256576 PMCID: PMC5335616 DOI: 10.1038/srep43767] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 01/30/2017] [Indexed: 11/09/2022] Open
Abstract
We report on the syntheses and characterizations of single crystalline and polycrystalline Sr2Co3S2O3 with a novel crystal structure type. It contains Co-O 2-leg rectangular ladders and necklace ladders. The two ladders share common legs and construct a hybrid spin ladder. A rare meridional heteroleptic octahedral coordination is found for the Co2+ ions in the 2-leg ladder. Within the necklace ladders, the Co2+ ions are in trans-octahedral coordination. An antiferromagnetic order is observed at TN ~ 267 K, while a broad maximum in magnetic susceptibility is found below TN. This relatively high ordering temperature among Co-based ladder compounds is related to the highly anisotropic mer-coordination of the Co2+ ions. The trans-octahedrally coordinated Co2+ ions, on the other hand, corresponds to the possible short-range magnetic correlations through dimers with an effective . This results in a rare situation that spin ordering and spin dimers coexist down to 2 K.
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Affiliation(s)
- Kwing To Lai
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany
| | - Martin Valldor
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany
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28
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Valldor M, Merz P, Prots Y, Watier Y, Schnelle W. Synthesis and Characterization of Cs 1-xTi 2Te 2O (x ≈ 0.2): Electron Doping by Te Resulting in a Layered Metal. Inorg Chem 2016; 55:11337-11341. [PMID: 27740772 DOI: 10.1021/acs.inorgchem.6b01903] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reacting Cs2O1.3, TiTe, TiO2, and Te under inert conditions gives powders of Cs1-xTi2Te2O (x ≈ 0.2). Small single crystals of the same phase were obtained from a CsCl salt melt in closed ampoules. This cesium dititanium ditelluride oxide (P4/mmm, a = 4.0934(3) Å, c = 8.9504(9) Å) is isostructural to CeCr2Si2C and contains layers of face-sharing trans-TiTe4O2 octahedra that are separated by Cs. As Ti occupies only one crystallographic site, its average oxidation state is +2.6, for the Cs deficit x = 0.2. The formally intermediate Ti valence state agrees well with the metallic conductivity and temperature-independent paramagnetic behavior. No superconductivity is observed down to 0.1 K in Cs0.8Ti2Te2O, but the fact that this structure type can accommodate Te2- suggests that electron doping of structurally closely related pnictide oxide superconductors, for example, BaTi2Bi2O, might be possible.
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Affiliation(s)
- Martin Valldor
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Patrick Merz
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Yurii Prots
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Yves Watier
- ESRF, The European Synchrotron , 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Walter Schnelle
- Max Planck Institute for Chemical Physics of Solids , Nöthnitzer Straße 40, 01187 Dresden, Germany
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29
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Wright T, Prots Y, Valldor M. Fused Perovskite Tunnel Structures in Ba 5
Fe 6+x
S 4+x
O 8
(0.44≤ x
≤0.55) with x
-Dependent Two-Stage Magnetizations. Chemistry 2016; 22:11303-9. [DOI: 10.1002/chem.201600997] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 05/25/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Taylor Wright
- Max Planck Institute for Chemical Physics of Solids; 01187 Dresden Germany
| | - Yurii Prots
- Max Planck Institute for Chemical Physics of Solids; 01187 Dresden Germany
| | - Martin Valldor
- Max Planck Institute for Chemical Physics of Solids; 01187 Dresden Germany
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Valldor M, Wright T, Fitch A, Prots Y. Metal Vacancy Ordering in an Antiperovskite Resulting in Two Modifications of Fe
2
SeO. Angew Chem Int Ed Engl 2016; 55:9380-3. [PMID: 27309149 DOI: 10.1002/anie.201603920] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Martin Valldor
- Max Planck Institute for Chemical Physics of Solids 01187 Dresden Germany
| | - Taylor Wright
- Max Planck Institute for Chemical Physics of Solids 01187 Dresden Germany
| | - Andrew Fitch
- ESRF, The European Synchrotron 71 Avenue des Martyrs 38000 Grenoble France
| | - Yurii Prots
- Max Planck Institute for Chemical Physics of Solids 01187 Dresden Germany
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31
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Valldor M, Wright T, Fitch A, Prots Y. Metal Vacancy Ordering in an Antiperovskite Resulting in Two Modifications of Fe
2
SeO. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201603920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Martin Valldor
- Max Planck Institute for Chemical Physics of Solids 01187 Dresden Germany
| | - Taylor Wright
- Max Planck Institute for Chemical Physics of Solids 01187 Dresden Germany
| | - Andrew Fitch
- ESRF, The European Synchrotron 71 Avenue des Martyrs 38000 Grenoble France
| | - Yurii Prots
- Max Planck Institute for Chemical Physics of Solids 01187 Dresden Germany
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32
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Valldor M, Böhme B, Prots Y, Borrmann H, Adler P, Schnelle W, Watier Y, Kuo CY, Pi TW, Hu Z, Felser C, Tjeng LH. [Cs6
Cl][Fe24
Se26
]: A Host-Guest Compound with Unique Fe-Se Topology. Chemistry 2016; 22:4626-31. [DOI: 10.1002/chem.201504840] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Martin Valldor
- Max Planck Institute for Chemical Physics of Solids; 01187 Dresden Germany
| | - Bodo Böhme
- Max Planck Institute for Chemical Physics of Solids; 01187 Dresden Germany
| | - Yurii Prots
- Max Planck Institute for Chemical Physics of Solids; 01187 Dresden Germany
| | - Horst Borrmann
- Max Planck Institute for Chemical Physics of Solids; 01187 Dresden Germany
| | - Peter Adler
- Max Planck Institute for Chemical Physics of Solids; 01187 Dresden Germany
| | - Walter Schnelle
- Max Planck Institute for Chemical Physics of Solids; 01187 Dresden Germany
| | - Yves Watier
- ESRF; 71 Avenue des Martyrs 38000 Grenoble France
| | - Chang Yang Kuo
- Max Planck Institute for Chemical Physics of Solids; 01187 Dresden Germany
| | - Tun-Wen Pi
- National Synchrotron Radiation Research Centre; Hsinchu 30076 Taiwan
| | - Zhiwei Hu
- Max Planck Institute for Chemical Physics of Solids; 01187 Dresden Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids; 01187 Dresden Germany
| | - Liu Hao Tjeng
- Max Planck Institute for Chemical Physics of Solids; 01187 Dresden Germany
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33
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Affiliation(s)
- Martin Valldor
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Straße 40, 01189 Dresden, Germany, http://www.cpfs.mpg.de/
| | - Patrick Merz
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Straße 40, 01189 Dresden, Germany, http://www.cpfs.mpg.de/
| | - Yurii Prots
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Straße 40, 01189 Dresden, Germany, http://www.cpfs.mpg.de/
| | - Walter Schnelle
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Straße 40, 01189 Dresden, Germany, http://www.cpfs.mpg.de/
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34
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Gerhards H, Krest A, Eulgem PJ, Naumann D, Rokitta D, Valldor M, Klein A. Syntheses and coordination chemistry of perfluoroaryl-1H-tetrazoles. Polyhedron 2015. [DOI: 10.1016/j.poly.2015.08.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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35
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Valldor M, Rößler UK, Prots Y, Kuo CY, Chiang JC, Hu Z, Pi TW, Kniep R, Tjeng LH. Synthesis and Characterization of Ba[CoSO]: Magnetic Complexity in the Presence of Chalcogen Ordering. Chemistry 2015; 21:10821-8. [PMID: 26079821 DOI: 10.1002/chem.201501024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Indexed: 11/07/2022]
Abstract
Barium thio-oxocobaltate(II), Ba[CoS2/2 O2/2 ], was synthesized by the reaction of equimolar amounts of BaO, Co, and S in closed silica ampoules. The title compound (Cmcm, a=3.98808(3), b=12.75518(9), c=6.10697(4) Å) is isostructural to Ba[ZnSO]. The use of soft X-ray absorption spectroscopy confirmed that cobalt is in the oxidation state +2 and tetrahedrally coordinated. Its coordination consists of two sulfur and two oxygen atoms in an ordered fashion. High-temperature magnetic susceptibility data indicate strong low-dimensional spin-spin interactions, which are suggested to be closely related to the layer-type crystal structure and perhaps the ordered distribution of sulfur and oxygen. Antiferromagnetic ordering below TN =222 K is observed as an anomaly in the specific heat, coinciding with a significant lowering of the magnetic susceptibility. Density functional theory calculations within a generalized-gradient approximation (GGA)+U approach identify an antiferromagnetic ground state within the square-like two-dimensional layers of Co, and antiferromagnetic correlations for nearest and next nearest neighbors along bonds mediated by oxygen or sulfur. However, this magnetic state is subject to frustration by relatively strong interlayer couplings.
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Affiliation(s)
- Martin Valldor
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden (Germany).
| | - Ulrich K Rößler
- Leibniz Institute for Solid State and Materials Research, Helmholtzstrasse 20, 01069 Dresden (Germany)
| | - Yurii Prots
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden (Germany)
| | - Chang-Yang Kuo
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden (Germany)
| | - Jen-Che Chiang
- Institute of Physics, National Chiao Tung University, Hsinchu 30010 (Taiwan)
| | - Zhiwei Hu
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden (Germany)
| | - Tun-Wen Pi
- National Synchrotron Radiation Research Centre, Hsinchu 30076 (Taiwan)
| | - Rüdiger Kniep
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden (Germany)
| | - Liu Hao Tjeng
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden (Germany)
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36
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Affiliation(s)
- Sungjoon Huh
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01189 Dresden, Germany, http://www.cpfs.mpg.de/
- University of British Columbia, 2329 West Mall, Vancouver, BC V6T 1Z4, Canada
| | - Yurii Prots
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01189 Dresden, Germany, http://www.cpfs.mpg.de/
| | - Peter Adler
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01189 Dresden, Germany, http://www.cpfs.mpg.de/
| | - Liu Hao Tjeng
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01189 Dresden, Germany, http://www.cpfs.mpg.de/
| | - Martin Valldor
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01189 Dresden, Germany, http://www.cpfs.mpg.de/
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37
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Hopkins EJ, Prots Y, Burkhardt U, Watier Y, Hu Z, Kuo CY, Chiang JC, Pi TW, Tanaka A, Tjeng LH, Valldor M. Ba3 v2 s4 o3 : a mott insulating frustrated quasi-one-dimensional s=1 magnet. Chemistry 2015; 21:7938-43. [PMID: 25876532 DOI: 10.1002/chem.201406511] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Indexed: 11/11/2022]
Abstract
Through a solid-state reaction, a practically phase pure powder of Ba3 V2 S4 O3 was obtained. The crystal structure was confirmed by X-ray single-crystal and synchrotron X-ray powder diffraction (P63 , a=10.1620(2), c=5.93212(1) Å). X-ray absorption spectroscopy, in conjunction with multiplet calculations, clearly describes the vanadium in charge-disproportionated V(III) S6 and V(V) SO3 coordinations. The compound is shown to be a strongly correlated Mott insulator, which contradicts previous predictions. Magnetic and specific heat measurements suggest dominant antiferromagnetic spin interactions concomitant with a weak residual ferromagnetic component, and that intrinsic geometric frustration prevents long-range order from evolving.
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Affiliation(s)
- Emily J Hopkins
- Physics of Correlated Matter, Max Planck Institute for Chemical Physics of Solids, 01187 Dresden (Germany)
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38
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Xiao L, Mertens M, Wortmann L, Kremer S, Valldor M, Lammers T, Kiessling F, Mathur S. Enhanced in vitro and in vivo cellular imaging with green tea coated water-soluble iron oxide nanocrystals. ACS Appl Mater Interfaces 2015; 7:6530-6540. [PMID: 25729881 DOI: 10.1021/am508404t] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Fully green and facile redox chemistry involving reduction of colloidal iron hydroxide (Fe(OH)3) through green tea (GT) polyphenols produced water-soluble Fe3O4 nanocrystals coated with GT extracts namely epigallocatechin gallate (EGCG) and epicatechin (EC). Electron donating polyphenols stoichiometrically reduced Fe(3+) ions into Fe(2+) ions resulting in the formation of magnetite (Fe3O4) nanoparticles and corresponding oxidized products (semiquinones and quinones) that simultaneously served as efficient surface chelators for the Fe3O4 nanoparticles making them dispersible and stable in water, PBS, and cell culture medium for extended time periods. As-formed iron oxide nanoparticles (2.5-6 nm) displayed high crystallinity and saturation magnetization as well as high relaxivity ratios manifested in strong contrast enhancement observed in T2-weighted images. Potential of green tea-coated superparamagnetic iron oxide nanocrystals (SPIONs) as superior negative contrast agents was confirmed by in vitro and in vivo experiments. Primary human macrophages (J774A.1) and colon cancer cells (CT26) were chosen to assess cytotoxicity and cellular uptake of GT-, EGCGq-, and ECq-coated Fe3O4 nanoparticles, which showed high uptake efficiencies by J774A.1 and CT26 cells without any additional transfection agent. Furthermore, the in vivo accumulation characteristics of GT-coated Fe3O4 nanoparticles were similar to those observed in clinical studies of SPIONs with comparable accumulation in epidermoid cancer-xenograft bearing mice. Given their promising transport and uptake characteristics and new surface chemistry, GT-SPIONs conjugates can be applied for multimodal imaging and therapeutic applications by anchoring further functionalities.
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Affiliation(s)
- Lisong Xiao
- †Institute of Inorganic Chemistry, University of Cologne, D-50939 Cologne, Germany
| | - Marianne Mertens
- ‡Department of Experimental Molecular Imaging, RWTH Aachen University Hospital, D-52074 Aachen, Germany
| | - Laura Wortmann
- †Institute of Inorganic Chemistry, University of Cologne, D-50939 Cologne, Germany
| | - Silke Kremer
- †Institute of Inorganic Chemistry, University of Cologne, D-50939 Cologne, Germany
| | - Martin Valldor
- §Max-Planck-Institute for Chemical Physics and Solids, D-01187 Dresden, Germany
| | - Twan Lammers
- ‡Department of Experimental Molecular Imaging, RWTH Aachen University Hospital, D-52074 Aachen, Germany
| | - Fabian Kiessling
- ‡Department of Experimental Molecular Imaging, RWTH Aachen University Hospital, D-52074 Aachen, Germany
| | - Sanjay Mathur
- †Institute of Inorganic Chemistry, University of Cologne, D-50939 Cologne, Germany
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39
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Valldor M, Adler P, Prots Y, Burkhardt U, Tjeng LH. S
= 2 Spin Ladders in the Sulfide Oxide BaFe
2
S
2
O (Eur. J. Inorg. Chem. 36/2014). Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201490172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Martin Valldor
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Strasse 40, 01187 Dresden, Germany, http://www.cpfs.mpg.de/
| | - Peter Adler
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Strasse 40, 01187 Dresden, Germany, http://www.cpfs.mpg.de/
| | - Yurii Prots
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Strasse 40, 01187 Dresden, Germany, http://www.cpfs.mpg.de/
| | - Ulrich Burkhardt
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Strasse 40, 01187 Dresden, Germany, http://www.cpfs.mpg.de/
| | - Liu Hao Tjeng
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Strasse 40, 01187 Dresden, Germany, http://www.cpfs.mpg.de/
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40
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Valldor M, Adler P, Prots Y, Burkhardt U, Tjeng LH. S
= 2 Spin Ladders in the Sulfide Oxide BaFe
2
S
2
O. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201403101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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41
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Reim JD, Rosén E, Schweika W, Meven M, Leo NR, Meier D, Fiebig M, Schmidt M, Kuo CY, Pi TW, Hu Z, Valldor M. Structural invariance upon antiferromagnetic ordering in geometrically frustrated swedenborgite, CaBaCo2Fe2O7. J Appl Crystallogr 2014. [DOI: 10.1107/s1600576714023528] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
Abstract
Centimetre-sized single crystals of high-quality CaBaCo2Fe2O7were synthesized by the optical floating zone technique. The metal-to-metal stoichiometry and oxygen content were confirmed by spectroscopy and thermal reduction experiments. The hexagonal symmetryP63mc(No. 186) well describes the powder X-ray and neutron diffraction as well as single-crystal neutron diffraction at all measured temperatures. This symmetry is also consistent with optical second harmonic generation data obtained between 10 and 295 K. However, a satisfactory structure description from single-crystal neutron diffraction data needs an oxygen split position. Specific heat, magnetic susceptibility and powder neutron diffraction data indicate a magnetic phase transition atTN= 159 K to an antiferromagnetic ground state, but with a persisting hexagonal symmetry and intrinsic geometric frustration.
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42
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Affiliation(s)
- Martin Valldor
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Strasse 40, 01187 Dresden, Germany, http://www.cpfs.mpg.de/
| | - Peter Adler
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Strasse 40, 01187 Dresden, Germany, http://www.cpfs.mpg.de/
| | - Yurii Prots
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Strasse 40, 01187 Dresden, Germany, http://www.cpfs.mpg.de/
| | - Ulrich Burkhardt
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Strasse 40, 01187 Dresden, Germany, http://www.cpfs.mpg.de/
| | - Liu Hao Tjeng
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Strasse 40, 01187 Dresden, Germany, http://www.cpfs.mpg.de/
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43
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Wortmann L, Ilyas S, Niznansky D, Valldor M, Arroub K, Berger N, Rahme K, Holmes J, Mathur S. Bioconjugated iron oxide nanocubes: synthesis, functionalization, and vectorization. ACS Appl Mater Interfaces 2014; 6:16631-16642. [PMID: 25184762 DOI: 10.1021/am503068r] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A facile bottom-up approach for the synthesis of inorganic/organic bioconjugated nanoprobes based on iron oxide nanocubes as the core with a nanometric silica shell is demonstrated. Surface coating and functionalization protocols developed in this work offered good control over the shell thickness (8-40 nm) and enabled biovectorization of SiO2@Fe3O4 core-shell structures by covalent attachment of folic acid (FA) as a targeting unit for cellular uptake. The successful immobilization of folic acid was investigated both quantitatively (TGA, EA, XPS) and qualitatively (AT-IR, UV-vis, ζ-potential). Additionally, the magnetic behavior of the nanocomposites was monitored after each functionalization step. Cell viability studies confirmed low cytotoxicity of FA@SiO2@Fe3O4 conjugates, which makes them promising nanoprobes for targeted internalization by cells and their imaging.
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Affiliation(s)
- Laura Wortmann
- Institute of Inorganic Chemistry, University of Cologne , Greinstrasse 6, Cologne 50939, Germany
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44
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Wang G, Valldor M, Mallick B, Mudring AV. Ionothermal synthesis of open-framework metal phosphates with a Kagomé lattice network exhibiting canted anti-ferromagnetism†Electronic supplementary information (ESI) available: Cif files, atomic parameters, X-ray diffraction patterns, IR spectra, TG curves, and thermal ellipsoid plot and atomic label schemes of compound 1-4. See DOI: 10.1039/c4tc00290cClick here for additional data file. J Mater Chem C Mater 2014; 2:7417-7427. [PMID: 25580250 PMCID: PMC4285085 DOI: 10.1039/c4tc00290c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 06/05/2014] [Indexed: 06/04/2023]
Abstract
Four open-framework transition-metal phosphates; (NH4)2Co3(HPO4)2F4 (1), (NH4)Co3(HPO4)2(H2PO4)F2 (2), KCo3(HPO4)2(H2PO4)F2 (3), and KFe3(HPO4)2(H2PO4)F2 (4); are prepared by ionothermal synthesis using pyridinium hexafluorophosphate as the ionic liquid. Single-crystal X-ray diffraction analyses reveal that the four compounds contain cobalt/iron-oxygen/fluoride layers with Kagomé topology composed of interlinked face-sharing MO3F3/MO4F2 octahedra. PO3OH pseudo-tetrahedral groups augment the [M3O6F4] (1)/[M3O8F2] layers on both sides to give M3(HPO4)2F4 (1) and M3(HPO4)2F2 (2-4) layers. These layers are stacked along the a axis in a sequence AA…, resulting in the formation of a layer structure for (NH4)2Co3(HPO4)2F4(1). In NH4Co3(HPO4)2(H2PO4)F2 and KM3(HPO4)2(H2PO4)F2, the M3(HPO4)2F2 layers are stacked along the a axis in a sequence AA i … and are connected by [PO3(OH)] tetrahedra, giving rise to a 3-D open framework structure with 10-ring channels along the [001] direction. The negative charges of the inorganic framework are balanced by K+/NH4+ ions located within the channels. The magnetic transition metal cations themselves form layers with stair-case Kagomé topology. Magnetic susceptibility and magnetization measurements reveal that all four compounds exhibit a canted anti-ferromagnetic ground state (Tc = 10 or 13 K for Co and Tc = 27 K for Fe) with different canting angles. The full orbital moment is observed for both Co2+ and Fe2+.
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Affiliation(s)
- Guangmei Wang
- Inorganic Chemistry III - Materials Engineering and Characterization , Ruhr-Universität Bochum , D-44780 Bochum , Germany
| | - Martin Valldor
- Physics of Correlated Matter , Max Plank Institute for Chemical Physics of Solids , D-01187 Dresden , Germany
| | - Bert Mallick
- Inorganic Chemistry III - Materials Engineering and Characterization , Ruhr-Universität Bochum , D-44780 Bochum , Germany
| | - Anja-Verena Mudring
- Inorganic Chemistry III - Materials Engineering and Characterization , Ruhr-Universität Bochum , D-44780 Bochum , Germany ; Department of Materials Science and Engineering , Iowa State University, and Critital Materials Institute , Ames Laboratory , Ames , IA , USA
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45
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Grams CP, Valldor M, Garst M, Hemberger J. Critical speeding-up in the magnetoelectric response of spin-ice near its monopole liquid-gas transition. Nat Commun 2014; 5:4853. [PMID: 25188290 DOI: 10.1038/ncomms5853] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 07/31/2014] [Indexed: 11/09/2022] Open
Abstract
Competing interactions in the so-called spin-ice compounds stabilize a frustrated ground state with finite zero-point entropy and, interestingly, emergent magnetic monopole excitations. The properties of these monopoles are at the focus of recent research with particular emphasis on their quantum dynamics. It is predicted that each monopole also possesses an electric dipole moment, which allows to investigate their dynamics via the dielectric function ε(ν). Here we report on broadband spectroscopic measurements of ε(ν) in Dy2Ti2O7 down to temperatures of 200 mK with a specific focus on the critical end point present for a magnetic field along the crystallographic [111] direction. Clear critical signatures are revealed in the dielectric response when, similarly as in the liquid-gas transition, the density of monopoles changes in a critical manner. The dielectric relaxation time τ exhibits a critical speeding-up with a significant enhancement of 1/τ as the temperature is lowered towards the critical temperature. Besides demonstrating the magnetoelectric character of the emergent monopole excitations, our results corroborate the unique critical dynamics near the monopole condensation transition.
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Affiliation(s)
- Christoph P Grams
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, 50937 Köln, Germany
| | - Martin Valldor
- 1] II. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, 50937 Köln, Germany [2] Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - Markus Garst
- Institut für Theoretische Physik, Universität zu Köln, Zülpicher Strasse 77, 50937 Köln, Germany
| | - Joachim Hemberger
- II. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, 50937 Köln, Germany
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46
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Demazeau G, Baranov A, Pöttgen R, Kienle L, Möller MH, Hoffmann RD, Valldor M. An Anhydrous High-pressure Synthesis Route to Rutile Type RhO2. Zeitschrift für Naturforschung B 2014. [DOI: 10.1515/znb-2006-1206] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A new anhydrous high-pressure synthesis route was developed for rutile type RhO2. Rhodium(III) chloride was reacted with Na2O2 at 600 °C under an oxygen pressure of 200 MPa yielding RhO2 and NaCl. X-ray powder diffractometer data and TEM observations confirmed the rutile structure: P42/mnm, a = 448.7(1), c = 308.9(1) pm, x(O) = 0.3125(8), leading to Rh-O distances of 195.0 (4x) and 198.3 pm (2x) in the slightly elongated octahedra. Structural transformations associated with the production of oxygen vacancies can be initiated by electron-beam heating.
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Affiliation(s)
- Gérard Demazeau
- Institut de Chimie de la Matière Condensée de Bordeaux, Centre de Ressources Hautes Pressions (ICMCB–CNRS and ENSCPB), Université Bordeaux 1 ≪Sciences et Technologies≫, 87 Avenue du Docteur A. Schweitzer, 33608 Pessac Cedex, France
| | - Alexis Baranov
- Institut de Chimie de la Matière Condensée de Bordeaux, Centre de Ressources Hautes Pressions (ICMCB–CNRS and ENSCPB), Université Bordeaux 1 ≪Sciences et Technologies≫, 87 Avenue du Docteur A. Schweitzer, 33608 Pessac Cedex, France
- Department of Chemistry, Lomonosov University, 119992 Moscow, Russia
| | - Rainer Pöttgen
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, 48149 Münster, Germany
| | - Lorenz Kienle
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Manfred H. Möller
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, 48149 Münster, Germany
| | - Rolf-Dieter Hoffmann
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, 48149 Münster, Germany
| | - Martin Valldor
- Institut für Physik der Kondensierten Materie, Technische Universität Braunschweig, Mendelssohnstraße 3, 38106 Braunschweig, Germany
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Abstract
Abstract
The new silicide NbPdSi was prepared by melting the elements in an arc-furnace.Well-shaped single crystals were obtained by annealing the sample in an induction furnace. The structure of NbPdSi has been studied by X-ray powder and single crystal diffractometer data: TiNiSi type, Pnma, Z = 4, a=643.0(1), b=376.7(1), c=744.4(2) pm, wR2=0.0330, 346 F2 values, and 20 variables. The palladium and silicon atoms build up a three-dimensional [PdSi] network where each palladium atoms has a strongly distorted tetrahedral silicon coordination at Pd-Si ranging from 242 to 250 pm. The niobium atoms fill channels left in the [PdSi] network.
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Affiliation(s)
- Martin Valldor
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
| | - Rainer Pöttgen
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, D-48149 Münster, Germany
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Wang G, Valldor M, Spielberg ET, Mudring AV. Ionothermal Synthesis, Crystal Structure, and Magnetic Study of Co2PO4OH Isostructural with Caminite. Inorg Chem 2014; 53:3072-7. [DOI: 10.1021/ic4029904] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Guangmei Wang
- Inorganic
Chemistry III—Materials Engineering and Characterization, Ruhr-Universität Bochum, D-44780 Bochum, Germany
| | - Martin Valldor
- Physics
of Correlated Matter, Max-Planck-Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
| | - Eike T. Spielberg
- Inorganic
Chemistry III—Materials Engineering and Characterization, Ruhr-Universität Bochum, D-44780 Bochum, Germany
| | - Anja-Verena Mudring
- Inorganic
Chemistry III—Materials Engineering and Characterization, Ruhr-Universität Bochum, D-44780 Bochum, Germany
- Materials
Science and Engineering, Iowa State University, Ames, Iowa 50011, United States
- Critical
Materials Institute, Ames Laboratory, Ames, Iowa 50011, United States
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Chen JM, Chin YY, Valldor M, Hu Z, Lee JM, Haw SC, Hiraoka N, Ishii H, Pao CW, Tsuei KD, Lee JF, Lin HJ, Jang LY, Tanaka A, Chen CT, Tjeng LH. A complete high-to-low spin state transition of trivalent cobalt ion in octahedral symmetry in SrCo0.5Ru0.5O(3-δ). J Am Chem Soc 2014; 136:1514-9. [PMID: 24410074 DOI: 10.1021/ja4114006] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The complex metal oxide SrCo0.5Ru0.5O(3-δ) possesses a slightly distorted perovskite crystal structure. Its insulating nature infers a well-defined charge distribution, and the six-fold coordinated transition metals have the oxidation states +5 for ruthenium and +3 for cobalt as observed by X-ray spectroscopy. We have discovered that Co(3+) ion is purely high-spin at room temperature, which is unique for a Co(3+) in an octahedral oxygen surrounding. We attribute this to the crystal field interaction being weaker than the Hund's-rule exchange due to a relatively large mean Co-O distances of 1.98(2) Å, as obtained by EXAFS and X-ray diffraction experiments. A gradual high-to-low spin state transition is completed by applying high hydrostatic pressure of up to 40 GPa. Across this spin state transition, the Co Kβ emission spectra can be fully explained by a weighted sum of the high-spin and low-spin spectra. Thereby is the much debated intermediate spin state of Co(3+) absent in this material. These results allow us to draw an energy diagram depicting relative stabilities of the high-, intermediate-, and low-spin states as functions of the metal-oxygen bond length for a Co(3+) ion in an octahedral coordination.
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Affiliation(s)
- Jin-Ming Chen
- National Synchrotron Radiation Research Center , 101 Hsin Ann Road, Hsinchu 30076, Taiwan, R.O.C
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Steinberg S, Valldor M, Meyer G. Change of magnetic and electronic features through subtle substitution in cubic, non-centrosymmetric extended rare-earth metal cluster complexes {TR3}X3. J SOLID STATE CHEM 2013. [DOI: 10.1016/j.jssc.2013.08.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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