Crystal structure and magnetic properties of two new cobalt selenite halides: Co5(SeO3)4X2 (X=Cl, Br)
| Autor: | Richard Becker, Mladen Prester, Mats Johnsson, I. Zivkovic, Helmuth Berger, Ping Hui Lin, Djuro Drobac |
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| Rok vydání: | 2007 |
| Předmět: |
education.field_of_study
Chemistry Population Space group Crystal structure Zero field splitting Triclinic crystal system Condensed Matter Physics Oxo-halide Lone-pair elements Crystal structure determination Magnetic susceptibility Zero-field splitting Single-ion anisotropy Electronic Optical and Magnetic Materials Inorganic Chemistry Crystallography Nuclear magnetic resonance Materials Chemistry Ceramics and Composites Antiferromagnetism Physical and Theoretical Chemistry Isostructural education |
| Zdroj: | Journal of Solid State Chemistry. 180:1051-1059 |
| ISSN: | 0022-4596 |
| DOI: | 10.1016/j.jssc.2006.12.035 |
| Popis: | Two new isostructural cobalt selenite halides Co{sub 5}(SeO{sub 3}){sub 4}Cl{sub 2} and Co{sub 5}(SeO{sub 3}){sub 4}Br{sub 2} have been synthesized. They crystallize in the triclinic system space group P-1 with the following lattice parameters for Co{sub 5}(SeO{sub 3}){sub 4}Cl{sub 2}: a=6.4935(8) A, b=7.7288(8) A, c=7.7443(10) A, {alpha}=66.051(11){sup o}, {beta}=73.610(11){sup o}, {gamma}=81.268(9){sup o}, and Z=1. The crystal structures were solved from single-crystal X-ray data, R1=3.73 and 4.03 for Co{sub 5}(SeO{sub 3}){sub 4}Cl{sub 2} and Co{sub 5}(SeO{sub 3}){sub 4}Br{sub 2}, respectively. The new compounds are isostructural to Ni{sub 5}(SeO{sub 3}){sub 4}Br{sub 2}. Magnetic susceptibility measurements on oriented single-crystalline samples show anisotropic response in a broad temperature range. The anisotropic susceptibility is quantitatively interpreted within the zero-field splitting schemes for Co{sup 2+} and Ni{sup 2+} ions. Sharp low-temperature susceptibility features, at T {sub N}=18 and 20 K for Co{sub 5}(SeO{sub 3}){sub 4}Cl{sub 2} and Co{sub 5}(SeO{sub 3}){sub 4}Br{sub 2}, respectively, are ascribed to antiferromagnetic ordering in a minority magnetic subsystem. In isostructural Ni{sub 5}(SeO{sub 3}){sub 4}Br{sub 2} magnetically ordered subsystem represents a majority fraction (T {sub N}=46 K). Nevertheless, anisotropic susceptibility of Ni{sub 5}(SeO{sub 3}){sub 4}Br{sub 2} is dominated at low temperatures by a minority fraction, subject to single-ion anisotropy effects and increasingmore » population of S{sub z} =0 (singlet) ground state of octahedrally coordinated Ni{sup 2+}. - Graphical abstract: Two new iso-structural cobalt selenite halides Co{sub 5}(SeO{sub 3}){sub 4}Cl{sub 2} and Co{sub 5}(SeO{sub 3}){sub 4}Br{sub 2} have been synthesized which are iso-structural to Ni{sub 5}(SeO{sub 3}){sub 4}Br{sub 2}. Magnetic susceptibility measurements on oriented single-crystalline samples show anisotropic response in a broad temperature range, revealing significant single-ion anisotropy effects.« less |
| Databáze: | OpenAIRE |
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