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Golosovsky IV, Kibalin IA, Gukasov A, Roca AG, López-Ortega A, Estrader M, Vasilakaki M, Trohidou KN, Hansen TC, Puente-Orench I, Lelièvre-Berna E, Nogués J. Elucidating Individual Magnetic Contributions in Bi-Magnetic Fe 3 O 4 /Mn 3 O 4 Core/Shell Nanoparticles by Polarized Powder Neutron Diffraction. Small Methods 2023; 7:e2201725. [PMID: 37391272 DOI: 10.1002/smtd.202201725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 05/10/2023] [Indexed: 07/02/2023]
Abstract
Heterogeneous bi-magnetic nanostructured systems have had a sustained interest during the last decades owing to their unique magnetic properties and the wide range of derived potential applications. However, elucidating the details of their magnetic properties can be rather complex. Here, a comprehensive study of Fe3 O4 /Mn3 O4 core/shell nanoparticles using polarized neutron powder diffraction, which allows disentangling the magnetic contributions of each of the components, is presented. The results show that while at low fields the Fe3 O4 and Mn3 O4 magnetic moments averaged over the unit cell are antiferromagnetically coupled, at high fields, they orient parallel to each other. This magnetic reorientation of the Mn3 O4 shell moments is associated with a gradual evolution with the applied field of the local magnetic susceptibility from anisotropic to isotropic. Additionally, the magnetic coherence length of the Fe3 O4 cores shows some unusual field dependence due to the competition between the antiferromagnetic interface interaction and the Zeeman energies. The results demonstrate the great potential of the quantitative analysis of polarized neutron powder diffraction for the study of complex multiphase magnetic materials.
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Affiliation(s)
- I V Golosovsky
- National Research Center "Kurchatov Institute", B. P. Konstantinov Petersburg Nuclear Physics Institute, Gatchina, 188300, Russia
| | - I A Kibalin
- Laboratoire Léon Brillouin, CEA-CNRS, CE-Saclay, Gif-sur-Yvette, 91191, France
| | - A Gukasov
- Laboratoire Léon Brillouin, CEA-CNRS, CE-Saclay, Gif-sur-Yvette, 91191, France
| | - A G Roca
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, 08193, Spain
| | - A López-Ortega
- Departamento de Ciencias, Universidad Pública de Navarra, Pamplona, 31006, Spain
- Institute for Advanced Materials and Mathematics INAMAT2, Universidad Pública de Navarra, Pamplona, 31006, Spain
| | - M Estrader
- Departament de Química Inorgànica i Orgànica, carrer Martí i Franqués 1-11, Universitat de Barcelona, Barcelona, 08028, Spain
- Institut de Nanociència i Nanotecnologia IN2UB, carrer Martí i Franqués 1-11, Universitat de Barcelona, Barcelona, 08028, Spain
| | - M Vasilakaki
- Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", 153 10, Agia Paraskevi, Attiki, 15310, Greece
| | - K N Trohidou
- Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", 153 10, Agia Paraskevi, Attiki, 15310, Greece
| | - T C Hansen
- Institut Laue Langevin, 71 avenue des Martyrs, Grenoble, 38000, France
| | - I Puente-Orench
- Institut Laue Langevin, 71 avenue des Martyrs, Grenoble, 38000, France
- Instituto de NanoCiencia y Materiales de Aragón, Zaragoza, 50009, Spain
| | - E Lelièvre-Berna
- Institut Laue Langevin, 71 avenue des Martyrs, Grenoble, 38000, France
| | - J Nogués
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, 08193, Spain
- ICREA, Barcelona, 08010, Spain
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Karlsson D, Ek G, Cedervall J, Zlotea C, Møller KT, Hansen TC, Bednarčík J, Paskevicius M, Sørby MH, Jensen TR, Jansson U, Sahlberg M. Structure and Hydrogenation Properties of a HfNbTiVZr High-Entropy Alloy. Inorg Chem 2018; 57:2103-2110. [PMID: 29389120 DOI: 10.1021/acs.inorgchem.7b03004] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [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
A high-entropy alloy (HEA) of HfNbTiVZr was synthesized using an arc furnace followed by ball milling. The hydrogen absorption mechanism was studied by in situ X-ray diffraction at different temperatures and by in situ and ex situ neutron diffraction experiments. The body centered cubic (BCC) metal phase undergoes a phase transformation to a body centered tetragonal (BCT) hydride phase with hydrogen occupying both tetrahedral and octahedral interstitial sites in the structure. Hydrogen cycling of the alloy at 500 °C is stable. The large lattice strain in the HEA seems favorable for absorption in both octahedral and tetrahedral sites. HEAs therefore have potential as hydrogen storage materials because of favorable absorption in all interstitial sites within the structure.
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Affiliation(s)
- Dennis Karlsson
- Department of Chemistry-Ångström Laboratory, Uppsala University , Box 523, SE-751 20 Uppsala, Sweden
| | - Gustav Ek
- Department of Chemistry-Ångström Laboratory, Uppsala University , Box 523, SE-751 20 Uppsala, Sweden
| | - Johan Cedervall
- Department of Chemistry-Ångström Laboratory, Uppsala University , Box 523, SE-751 20 Uppsala, Sweden
| | - Claudia Zlotea
- Université Paris Est, Institut de Chimie et des Matériaux Paris-Est (UMR7182), CNRS, UPEC , 2-8 rue Henri Dunant, F-94320 Thiais, France
| | - Kasper Trans Møller
- Center for Materials Crystallography, iNANO, and Department of Chemistry, Aarhus University , Langelandsgade 140, 8000 Aarhus, Denmark
| | | | - Jozef Bednarčík
- Deutsches Elektronen-Synchrotron DESY, Photon Science, D-22607 Hamburg, Germany
| | - Mark Paskevicius
- Center for Materials Crystallography, iNANO, and Department of Chemistry, Aarhus University , Langelandsgade 140, 8000 Aarhus, Denmark
| | - Magnus Helgerud Sørby
- Institute for Energy Technology , Physics Department, P.O. Box 40, NO-2027 Kjeller, Norway
| | - Torben René Jensen
- Center for Materials Crystallography, iNANO, and Department of Chemistry, Aarhus University , Langelandsgade 140, 8000 Aarhus, Denmark
| | - Ulf Jansson
- Department of Chemistry-Ångström Laboratory, Uppsala University , Box 523, SE-751 20 Uppsala, Sweden
| | - Martin Sahlberg
- Department of Chemistry-Ångström Laboratory, Uppsala University , Box 523, SE-751 20 Uppsala, Sweden
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Abstract
Hydrides (deuterides) of the CrB-type Zintl phases AeTt (Ae = alkaline earth; Tt = tetrel) show interesting bonding properties with novel polyanions. In SrGeD4/3-x (γ phase), three zigzag chains of Ge atoms are condensed and terminated by covalently bound D atoms. A combination of in situ techniques (thermal analysis and synchrotron and neutron powder diffraction) revealed the existence of two further hydride (deuteride) phases with lower H (D) content (called α and β phases). Both are structurally related to the parent Zintl phase SrGe and to the ZrNiH structure type containing variable amounts of H (D) in Sr4 tetrahedra. For α-SrGeDy, the highest D content y = 0.29 was found at 575(2) K under 5.0(1) MPa of D2 pressure, and β-SrGeDy shows a homogeneity range of 0.47 < y < 0.63. Upon decomposition of SrGeD4/3-x (γ-SrGeDy), tetrahedral Sr4 voids stay filled, while the Ge-bound D4 site loses D. When reaching the lower D content limit, SrGeD4/3-x (γ phase) with 0.10 < x < 0.17, decomposes to the β phase. All three hydrides (deuterides) of SrGe show variable H (D) content.
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Affiliation(s)
- Henry Auer
- Department of Inorganic Chemistry, Leipzig University , Johannisalle 29, 04103 Leipzig, Germany
| | - Dirk Wallacher
- Helmholtz Zentrum Berlin für Materialien und Energie , Hahn-Meitner-Platz 1, 14109 Berlin, Germany
| | | | - Holger Kohlmann
- Department of Inorganic Chemistry, Leipzig University , Johannisalle 29, 04103 Leipzig, Germany
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Auer H, Guehne R, Bertmer M, Weber S, Wenderoth P, Hansen TC, Haase J, Kohlmann H. Hydrides of Alkaline Earth-Tetrel (AeTt) Zintl Phases: Covalent Tt-H Bonds from Silicon to Tin. Inorg Chem 2017; 56:1061-1071. [PMID: 28098994 DOI: 10.1021/acs.inorgchem.6b01944] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [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
Zintl phases form hydrides either by incorporating hydride anions (interstitial hydrides) or by covalent bonding of H to the polyanion (polyanionic hydrides), which yields a variety of different compositions and bonding situations. Hydrides (deuterides) of SrGe, BaSi, and BaSn were prepared by hydrogenation (deuteration) of the CrB-type Zintl phases AeTt and characterized by laboratory X-ray, synchrotron, and neutron diffraction, NMR spectroscopy, and quantum-chemical calculations. SrGeD4/3-x and BaSnD4/3-x show condensed boatlike six-membered rings of Tt atoms, formed by joining three of the zigzag chains contained in the Zintl phase. These new polyanionic motifs are terminated by covalently bound H atoms with d(Ge-D) = 1.521(9) Å and d(Sn-D) = 1.858(8) Å. Additional hydride anions are located in Ae4 tetrahedra; thus, the features of both interstitial hydrides and polyanionic hydrides are represented. BaSiD2-x retains the zigzag Si chain as in the parent Zintl phase, but in the hydride (deuteride), it is terminated by H (D) atoms, thus forming a linear (SiD) chain with d(Si-D) = 1.641(5) Å.
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Affiliation(s)
| | | | | | | | - Patrick Wenderoth
- Department of Inorganic Solid-State Chemistry, Saarland University , Am Markt, Zeile 3, 66125 Saarbrücken, Germany
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Ludl AA, Bove LE, Saitta AM, Salanne M, Hansen TC, Bull CL, Gaal R, Klotz S. Structural characterization of eutectic aqueous NaCl solutions under variable temperature and pressure conditions. Phys Chem Chem Phys 2015; 17:14054-63. [PMID: 25955540 DOI: 10.1039/c5cp00224a] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The structure of amorphous NaCl solutions produced by fast quenching is studied as a function of pressure, up to 4 GPa, by combined neutron diffraction experiments and classical molecular dynamics simulations. Similarly to LiCl solutions the system amorphizes at ambient pressure in a dense phase structurally similar to the e-HDA phase in pure water. The measurement of the static structure factor as a function of pressure allowed us to validate a new polarizable force field developed by Tazi et al., 2012, never tested under non-ambient conditions. We infer from simulations that the hydration shells of Na(+) cations form well defined octahedra composed of both H2O molecules and Cl(-) anions at low pressure. These octahedra are gradually broken by the seventh neighbour moving into the shell of first neighbours yielding an irregular geometry. In contrast to LiCl solutions and pure water, the system does not show a polyamorphic transition under pressure. This confirms that the existence of polyamorphism relies on the tetrahedral structure of water molecules, which is broken here.
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Affiliation(s)
- A-A Ludl
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7590, IMPMC, F-75005, Paris, France.
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Marcinkova A, Hansen TC, Bos JWG. Iron spin-reorientation transition in NdFeAsO. J Phys Condens Matter 2012; 24:256007. [PMID: 22641142 DOI: 10.1088/0953-8984/24/25/256007] [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: 06/01/2023]
Abstract
The low-temperature magnetic structure of NdFeAsO has been revisited using neutron powder diffraction and symmetry analysis using the Sarah representational analysis program. Four magnetic models with one magnetic variable for each of the Nd and Fe sublattices were tested. The best fit was obtained using a model with Fe moments pointing along the c-direction, and Nd moments along the a-direction. This signals a significant interplay between rare-earth and transition metal magnetism, which results in a spin-reorientation of the Fe sublattice upon ordering of the Nd moments. All models that fit the data well, including collinear models with more than one magnetic variable per sublattice, were found to have an Fe moment of 0.5 μ(B) and a Nd moment of 0.9 μ(B), demonstrating that the low-temperature Fe moment is not substantially enhanced compared to the spin-density wave state.
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Affiliation(s)
- A Marcinkova
- School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, UK
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Qureshi N, Fuess H, Ehrenberg H, Ouladdiaf B, Rodríguez-Carvajal J, Hansen TC, Wolf T, Meingast C, Zhang Q, Knafo W, Löhneysen HV. Magnetic structure of the kagome mixed compound (Co(0.5)Ni(0.5))(3)V(2)O(8). J Phys Condens Matter 2008; 20:235228. [PMID: 21694319 DOI: 10.1088/0953-8984/20/23/235228] [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: 05/30/2023]
Abstract
We report the magnetic structure of (Co(0.5)Ni(0.5))(3)V(2)O(8) (CNVO) deduced by single crystal neutron diffraction. This compound exhibits features which differ from that of its parent compounds, which are absolutely collinear along the a axis for Co(3)V(2)O(8) (CVO) or exhibit magnetic moments predominantly in the a-b plane with small components along c in the case of Ni(3)V(2)O(8) (NVO). The averaged magnetic moments of the statistically distributed Ni(2+) and Co(2+) ions in CNVO are oriented in the a-c plane and form loops of quasiferromagnetically coupled spins. These loops are connected along the a axis and separated along the c axis by cross-tie spins forming a quasiferromagnetic wave with the upper part of the respective neighbouring loops. The magnetic moments are sinusoidally modulated by the propagation vector k = (0.49,0,0) with an average amplitude of 1.59(1) μ(B) for a magnetic ion on a cross-tie site and 1.60(1) μ(B) for the spine site. In addition to neutron diffraction, specific heat and magnetization data, which confirm that the only magnetic phase transition above 1.8 K is the onset of antiferromagnetic order at T(N) = 7.4(1) K, are presented.
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Affiliation(s)
- N Qureshi
- Institute for Materials Science, University of Technology, D-64287 Darmstadt, Germany. Institut Max von Laue-Paul Langevin, 38042 Grenoble Cedex 9, France
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Walton RI, Millange F, Smith RI, Hansen TC, O'Hare D. Real time observation of the hydrothermal crystallization of barium titanate using in situ neutron powder diffraction. J Am Chem Soc 2001; 123:12547-55. [PMID: 11741419 DOI: 10.1021/ja011805p] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The hydrothermal crystallization of barium titanate, BaTiO3, has been studied in situ by time-resolved powder neutron diffraction methods using the recently developed Oxford/ISIS hydrothermal cell. This technique has allowed the formation of the ferroelectric ceramic to be followed in a noninvasive manner in real time and under genuine reaction conditions. In a first set of experiments, Ba(OD)2-8D2O was reacted with two different titanium sources, either crystalline TiO2 (anatase) or amorphous TiO2-H2O in D2O, at 100-140 degrees C and the reaction studied using the POLARIS time-of-flight neutron powder diffractometer, at the ISIS Facility. In a second series of experiments, the reaction between barium chloride and crystalline TiO2 (anatase) in NaOD/D2O was studied at temperatures between 100 and 200 degrees C and at different deuterioxide concentrations using the constant-wavelength D20 neutron powder diffractometer at the Institut Laue Langevin. Quantitative growth and decay curves were determined from analysis of the integrated intensities of Bragg reflections of starting materials and product phases. In both sets of experiments the rapid dissolution of the barium source was observed, followed by dissolution of the titanium source before the onset of crystallization of barium titanate. Using a nucleation-growth model we are able to simulate the growth curve of barium titanate at three temperatures. Our results indicate the predominance of a homogeneous dissolution-precipitation mechanism for the hydrothermal formation of barium titanate, rather than other possible mechanisms that have been discussed in the literature. Analysis of the line widths of the Bragg reflections in the neutron diffraction data indicates that the particle size of the BaTiO3 product phase prepared from the amorphous TiO2-H2O is smaller than that prepared from crystalline TiO2 (anatase).
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Affiliation(s)
- R I Walton
- School of Chemistry, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
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