High resolution powder diffraction studies are reported for the series of mixed RuIr perovskites Sr2TbRu1-xIr xO6. Using a combination of synchrotron X-ray and neutron powder diffraction precise structures are established for the two end-member oxides, where the Tb oxidation state changes from +3 in the Ru oxide to +4 in the Ir containing oxide. The structures of both oxides are monoclinic. Composition dependent studies show that this valence transition is first order. Variable temperature diffraction show no evidence for any structural or valence state transitions. However, upon application of pressure Sr2TbRu 0.3Ir0.7O6 undergoes a valence state transition at low pressures.
Bibliographical noteFunding Information:
BJK thanks the Australian Research Council for support for his work on perovskites. The work performed at the Australian National Beamline Facility was supported by the Australian Synchrotron Research Program, which is funded by the Commonwealth of Australia under the Major National Research Facilities program. The Australian Institute of Nuclear Science and Engineering supported the neutron diffraction experiments. Work at Brookhaven is supported by the US Department of Energy, Division of Materials Sciences under contract No. DE-AC02-98CH10886. The assistance of Dr. James Hester at the ANBF is gratefully acknowledged.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry