Static disorder from lone-pair electrons in pyrochlores
| Autor: | Robert J. Cava, Maxim Avdeev, M. K. Haas, James D. Jorgensen |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Rietveld refinement
Chemistry Neutron diffraction chemistry.chemical_element Crystal structure Electronic structure Condensed Matter Physics Electronic Optical and Magnetic Materials Bismuth Inorganic Chemistry Crystallography Vacancy defect Materials Chemistry Ceramics and Composites Physical and Theoretical Chemistry Electronic band structure Lone pair |
| Zdroj: | Journal of Solid State Chemistry. 169:24-34 |
| ISSN: | 0022-4596 |
| DOI: | 10.1016/s0022-4596(02)00007-5 |
| Popis: | The crystal structures of Bi2Ru2O7 and Bi 1.6 M 0.4 Ru 2 O 7 (M= Cu,Co ) pyrochlores are determined by Rietveld refinement of neutron powder diffraction data collected between 300 and 12 K . An appreciable oxygen non-stoichiometry, with no vacancy ordering, is found only in undoped Bi2Ru2O7. In all three compounds, static displacive disorder of both the Bi and O′ sites is observed. This type of disorder has not been reported previously for Bi2Ru2O7, and is proposed to be a common feature of A2B2O7 pyrochlores having a lone electronic pair on the A-site cation. The electronic properties of Bi2Ru2O7 are discussed in terms of calculated electronic band structure, local ruthenium coordination, and the static bismuth displacement. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect