Structural studies of the phases in Ba{sub 2}LaIrO{sub 6}-New light on an old problem
- School of Chemistry, University of Sydney, Sydney, NSW 2006 (Australia)
- Bragg Institute, Australian Nuclear Science and Technology Organisation, Private Mail Bag 1, Menai NSW 2234 (United States)
- Australian Synchrotron, 800 Blackburn Rd, Clayton, Victoria 3168 (Australia)
Accurate and precise structures for the cation-ordered double perovskite Ba{sub 2}LaIrO{sub 6} at a number of temperatures are presented. Careful analysis of the synchrotron X-ray and neutron diffraction profiles of Ba{sub 2}LaIrO{sub 6} suggests that, at room temperature, this is monoclinic in space group I2/m. Heating the sample to 375 K results in a transition to a rhombohedral phase in R3-bar with further heating resulting in the loss of the tilting of the octahedra, the structure being in Fm3-bar m. Cooling the sample induces an additional phase transition to a triclinic structure in I1-bar . Details of the various structures are presented. - Graphical abstract Text3: Variable temperature neutron and synchrotron X-ray powder diffraction methods have been used to resolve the long standing question regarding the symmetry and structure of the cation-ordered perovskite Ba{sub 2}LaIrO{sub 6}. We show this is monoclinic in I2/m at room temperature, with the sequence of phases I1-bar->I2/m->R3-bar->Fm3-barm.
- OSTI ID:
- 21372407
- Journal Information:
- Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 11 Vol. 182; ISSN 0022-4596; ISSN JSSCBI
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COHERENT SCATTERING
COOLING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CUBIC LATTICES
DIFFRACTION
HEATING
IRIDIUM COMPOUNDS
IRIDIUM OXIDES
LANTHANUM COMPOUNDS
MINERALS
MONOCLINIC LATTICES
NEUTRON DIFFRACTION
NEUTRON TEMPERATURE
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PEROVSKITE
PEROVSKITES
PHASE TRANSFORMATIONS
RARE EARTH COMPOUNDS
REFRACTORY METAL COMPOUNDS
SCATTERING
SPACE GROUPS
SYMMETRY GROUPS
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K
TRANSITION ELEMENT COMPOUNDS
TRIGONAL LATTICES
X-RAY DIFFRACTION