Crystal Structures and Magnetic Properties of Mixed Iridium-Ruthenium Triple Perovskites. 2. Ba3MRuIrO9 (M = Li, Na, Mg, Ni, Zn, Bi, In)
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- 作者：Michael W. Lufaso and Hans-Conrad zur Loye
- 刊名：Inorganic Chemistry
- 出版年：2005
- 出版时间：December 12, 2005
- 年：2005
- 卷：44
- 期：25
- 页码：9154 - 9161
- 全文大小：216K
- 年卷期：v.44,no.25(December 12, 2005)
- ISSN：1520-510X
文摘
Crystal structures and magnetic properties of polycrystalline Ba3MRuIrO9 (M1+ = Li, Na; M2+ = Mg, Ni, Zn; M3+ =Bi, In) were investigated. Rietveld refinements of the crystal structures using powder diffraction data indicate that,with the exception of Ba3BiRuIrO9, all compounds crystallize in the 6H-BaTiO3 structure type in space groupP63/mmc; Ba3BiRuIrO9 crystallizes in space group C2/c. The 6H-BaTiO3, or triple-perovskite, structure is composedof hexagonal and cubic stacking of [AO3] layers and contains face- and corner-sharing octahedra. The structuresin this study contain a disordered mixture of Ir and Ru in the face-sharing octahedra dimers, which are connectedvia corner-shared MO6 octahedra. Magnetic susceptibility measurements as a function of temperature were carriedout on each compound. Effective magnetic moments were smaller than values estimated using spin-only moments,which indicate the presence of spin-orbit coupling and strong interactions in the face-sharing octahedra that containa disordered mixture of Ru and Ir on a single crystallographic site. Over a broad temperature range, a divergenceof the zero-field-cooled and field-cooled data were observed for Ba3MgRuIrO9, Ba3NiRuIrO9, Ba3ZnRuIrO9, andBa3LiRuIrO9.