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Akin ST, Zamudio-Bayer V, Duanmu K, Leistner G, Hirsch K, Bülow C, Ławicki A, Terasaki A, Issendorff BV, Truhlar DG, Lau JT, Duncan MA. Size-Dependent Ligand Quenching of Ferromagnetism in Co 3(benzene) n+ Clusters Studied with X-ray Magnetic Circular Dichroism Spectroscopy. J Phys Chem Lett 2016; 7:4568-4575. [PMID: 27779876 DOI: 10.1021/acs.jpclett.6b01839] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Cobalt-benzene cluster ions of the form Co3(bz)n+ (n = 0-3) were produced in the gas phase, mass-selected, and cooled in a cryogenic ion trap held at 3-4 K. To explore ligand effects on cluster magnetic moments, these species were investigated with X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) spectroscopy. XMCD spectra yield both the spin and orbital angular momenta of these clusters. Co3+ has a spin magnetic moment of μS = 6 μB and an orbital magnetic moment of μL = 3 μB. Co3(bz)+ and Co3(bz)2+ complexes were found to have spin and orbital magnetic moments identical to the values for ligand-free Co3+. However, coordination of the third benzene to form Co3(bz)3+ completely quenches the high spin state of the system. Density functional theory calculations elucidate the spin states of the Co3(bz)n+ species as a function of the number of attached benzene ligands, explaining the transition from septet to singlet for n = 0 → 3.
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Affiliation(s)
- Scott T Akin
- Department of Chemistry, University of Georgia , Athens, Georgia 30602, United States
| | - Vicente Zamudio-Bayer
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
- Physikalisches Institut, Universität Freiburg , Stefan-Meier-Straße 21, 79104 Freiburg, Germany
| | - Kaining Duanmu
- Department of Chemistry, Chemical Theory Center, and the Supercomputing Institute, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Georg Leistner
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
- Institut für Optik und Atomare Physik, Technische Universität Berlin , Hardenbergstraße 36, 10623 Berlin, Germany
| | - Konstantin Hirsch
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
- Institut für Optik und Atomare Physik, Technische Universität Berlin , Hardenbergstraße 36, 10623 Berlin, Germany
| | - Christine Bülow
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
- Institut für Optik und Atomare Physik, Technische Universität Berlin , Hardenbergstraße 36, 10623 Berlin, Germany
| | - Arkadiusz Ławicki
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Akira Terasaki
- East Tokyo Laboratory, Genesis Research Institute, Inc. , 717-86 Futamata, Ichikawa, Chiba 272-0001, Japan
- Department of Chemistry, Faculty of Science, Kyushu University , 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Bernd von Issendorff
- Physikalisches Institut, Universität Freiburg , Stefan-Meier-Straße 21, 79104 Freiburg, Germany
| | - Donald G Truhlar
- Department of Chemistry, Chemical Theory Center, and the Supercomputing Institute, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - J Tobias Lau
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Michael A Duncan
- Department of Chemistry, University of Georgia , Athens, Georgia 30602, United States
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Bennemann K. Magnetic nanostructures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:243201. [PMID: 21393778 DOI: 10.1088/0953-8984/22/24/243201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Characteristic results of magnetism in small particles, thin films and tunnel junctions are presented. As a consequence of the reduced atomic coordination in small clusters and thin films the electronic states and density of states are modified. Thus, magnetic moments and magnetization are affected. Generally, in clusters and thin films magnetic anisotropy plays a special role. In tunnel junctions the interplay of magnetism, spin currents and superconductivity are of particular interest. In ring-like mesoscopic systems Aharonov-Bohm-induced currents are studied. Results are given for single transition metal clusters, cluster ensembles, thin films, mesoscopic structures and tunnel systems.
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Affiliation(s)
- K Bennemann
- Institute of Theoretical Physics, FU-Berlin, Arnimallee 14, D-14195 Berlin, Germany
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Li X, Eustis S, Bowen KH, Kandalam AK, Jena P. Photoelectron spectroscopic and theoretical studies of Fem−(coronene)n (m=1,2, n=1,2) complexes. J Chem Phys 2008; 129:074313. [DOI: 10.1063/1.2968609] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Knickelbein MB. Magnetic moments of bare and benzene-capped cobalt clusters. J Chem Phys 2007; 125:44308. [PMID: 16942143 DOI: 10.1063/1.2217951] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Magnetic moments of bare cobalt clusters Co(n) (n=7-32) and benzene-capped cobalt clusters Co(n)(bz)(m) have been measured at temperatures ranging from 54 to 150 K using a molecular beam deflection method. It was observed that Co(12-32) produced at temperatures greater than approximately 100 K display high-field-seeking behavior at all temperatures in the range investigated, indicating that they are superparamagnetic species. At temperatures below approximately 100 K, the field-on beam profiles of Co(7-11) and some larger clusters displayed substantial symmetric broadening, indicating that some fraction of the clusters in the beam were no longer superparamagnetic, but rather were in a blocked (locked-moment) state. In the superparamagnetic regime (T=150 K) Co(n) clusters in the n=7-32 size range were found to possess per-atom moments ranging from 1.96+/-0.04 micro(b)(Co(24)) to 2.53+/-0.04 micro(b)(Co(16)), significantly above the bulk value of 1.72 micro(b). Locked-moment isomers were found to display moments of approximately 1 micro(b) per atom. Cobalt clusters containing a layer of adsorbed benzene molecules were found to possess significantly lower moments per cobalt atom than the corresponding bare cobalt clusters.
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Affiliation(s)
- Mark B Knickelbein
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
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Brenner JR, Marshall CL, Nieman GC, Parks EK, Riley SJ, Ellis L, Tomczyk NA, Winans RE. Structural Characterization of Rhodium-Containing Hydrodesulfurization (HDS) Catalysts Derived from a Laser Vaporization Cluster Source. J Catal 1997. [DOI: 10.1006/jcat.1997.1522] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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