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Xue Z, Ramirez‐Cuesta AJ, Brown CM, Calder S, Cao H, Chakoumakos BC, Daemen LL, Huq A, Kolesnikov AI, Mamontov E, Podlesnyak AA, Wang X. Neutron Instruments for Research in Coordination Chemistry. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201801076] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Zi‐Ling Xue
- Department of Chemistry University of Tennessee 37996 Knoxville Tennessee United States
| | - Anibal J. Ramirez‐Cuesta
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Craig M. Brown
- Center for Neutron Research National Institute of Standards and Technology 20899 Gaithersburg Maryland United States
- Department of Chemical and Biomolecular Engineering University of Delaware 19716 Newark Delaware United States
| | - Stuart Calder
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Huibo Cao
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Bryan C. Chakoumakos
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Luke L. Daemen
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Ashfia Huq
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Alexander I. Kolesnikov
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Eugene Mamontov
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Andrey A. Podlesnyak
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
| | - Xiaoping Wang
- Neutron Scattering Division Oak Ridge National Laboratory 37831 Oak Ridge Tennessee United States
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Chen L, Cui HH, Stavretis SE, Hunter SC, Zhang YQ, Chen XT, Sun YC, Wang Z, Song Y, Podlesnyak AA, Ouyang ZW, Xue ZL. Slow Magnetic Relaxations in Cobalt(II) Tetranitrate Complexes. Studies of Magnetic Anisotropy by Inelastic Neutron Scattering and High-Frequency and High-Field EPR Spectroscopy. Inorg Chem 2016; 55:12603-12617. [PMID: 27989182 DOI: 10.1021/acs.inorgchem.6b01544] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Three mononuclear cobalt(II) tetranitrate complexes (A)2[Co(NO3)4] with different countercations, Ph4P+ (1), MePh3P+ (2), and Ph4As+ (3), have been synthesized and studied by X-ray single-crystal diffraction, magnetic measurements, inelastic neutron scattering (INS), high-frequency and high-field EPR (HF-EPR) spectroscopy, and theoretical calculations. The X-ray diffraction studies reveal that the structure of the tetranitrate cobalt anion varies with the countercation. 1 and 2 exhibit highly irregular seven-coordinate geometries, while the central Co(II) ion of 3 is in a distorted-dodecahedral configuration. The sole magnetic transition observed in the INS spectroscopy of 1-3 corresponds to the zero-field splitting (2(D2 + 3E2)1/2) from 22.5(2) cm-1 in 1 to 26.6(3) cm-1 in 2 and 11.1(5) cm-1 in 3. The positive sign of the D value, and hence the easy-plane magnetic anisotropy, was demonstrated for 1 by INS studies under magnetic fields and HF-EPR spectroscopy. The combined analyses of INS and HF-EPR data yield the D values as +10.90(3), +12.74(3), and +4.50(3) cm-1 for 1-3, respectively. Frequency- and temperature-dependent alternating-current magnetic susceptibility measurements reveal the slow magnetization relaxation in 1 and 2 at an applied dc field of 600 Oe, which is a characteristic of field-induced single-molecule magnets (SMMs). The electronic structures and the origin of magnetic anisotropy of 1-3 were revealed by calculations at the CASPT2/NEVPT2 level.
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Affiliation(s)
- Lei Chen
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210023, People's Republic of China
| | - Hui-Hui Cui
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210023, People's Republic of China
| | - Shelby E Stavretis
- Department of Chemistry, University of Tennessee , Knoxville, Tennessee 37996, United States
| | - Seth C Hunter
- Department of Chemistry, University of Tennessee , Knoxville, Tennessee 37996, United States
| | - Yi-Quan Zhang
- Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University , Nanjing 210023, People's Republic of China
| | - Xue-Tai Chen
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210023, People's Republic of China
| | - Yi-Chen Sun
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology , Wuhan 430074, People's Republic of China
| | - Zhenxing Wang
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology , Wuhan 430074, People's Republic of China
| | - You Song
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210023, People's Republic of China
| | - Andrey A Podlesnyak
- Quantum Condensed Matter Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Zhong-Wen Ouyang
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology , Wuhan 430074, People's Republic of China
| | - Zi-Ling Xue
- Department of Chemistry, University of Tennessee , Knoxville, Tennessee 37996, United States
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Liu XD, Zheng XG, Meng DD, Xu XL, Guo QX. Raman spectroscopic study of the frustrated spin 1/2 antiferromagnet clinoatacamite. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:256003. [PMID: 23719338 DOI: 10.1088/0953-8984/25/25/256003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Raman spectroscopy is a valuable and complementary tool for studying geometrically frustrated magnetic systems due to the intrinsic spin-phonon coupling. Here, we report on a Raman spectroscopic study of the geometrically frustrated spin 1/2 antiferromagnet microcrystalline clinoatacamite Cu2(OH)3Cl, focusing on the anomalous transition into the intermediate phase at T(c1) = 18.1 K. By measuring the temperature-dependent (295-4 K) full spectral profiles and main representative modes in spectral regions from 4000 to 95 cm(-1), we observed probable signatures of successive magnetic transitions near T(c1) = 18 K and T(c2) = 6.4 K in the Raman band frequencies and peak widths of the representative modes. Further, we observed a pronounced Raman spectroscopy background featuring a broad continuum at all temperatures. A quantitative analysis reveals that spin fluctuations may exist on a picosecond time scale in the intermediate phase. The short time scale falls out of the μSR time window; therefore, in the intermediate phase, the μSR study as reported in (2005 Phys. Rev. Lett. 95 057201) apparently only probed the local field of the ordered spins but overlooked the quickly fluctuating ones. This is likely to give a reasonable explanation of the fact that only a small entropy release occurs at T(c1) = 18 K although a long-range order is formed.
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Affiliation(s)
- Xiao-Dong Liu
- Department of Physics, Graduate School of Science and Engineering, Saga University, Saga 840-8502, Japan
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