Japanese Journal of Applied Physics · 1989 · 13 citations · 14 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsCrystal StructureSolid State PhysicsCrystal ChemistryCrystal LatticeCrystal SystemsCrystallographyX-ray CrystallographyX-ray DiffractionAnisotropic Thermal BehaviorAnisotropic Thermal PropertiesCrystallographic Symmetry AnalysisPerovskite Crystal StructurePowder DiffractionRietveld AnalysisTetragonal SystemUnit Cell Parameters
High-temperature crystal structures of BaBiO 3- x ( x =0∼0.2) were studied by in-situ neutron and X-ray powder diffraction techniques using controlled oxygen pressures. Rietveld profile analysis of the neutron data from BaBiO 3 at 900 K has revealed that the structure is cubic with large anisotropic thermal vibration amplitudes of the O ions perpendicular to the Bi–O bonds. For oxygen-deficient BaBiO 3- x , both the neutron and X-ray data showed that the system is not a single phase. The X-ray data from BaBiO 2.99 at 1010 K indicated a two-phase system comprising a cubic perovskite and a tetragonal structure with a doubled cell. Profile analyses gave refined cell parameters of a =6.293 and c =9.054 Å for the tetragonal phase. In more reduced BaBiO 2.8 at 1075 K this tetragonal structure was replaced by another pseudotetragonal structure with a slightly expanded cell.
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Crystal structure of Ba2Bi3+Bi5+O6
D. E. Cox, A.W. Sleight · Solid State Communications · 1976 · 432 citations