A systematic crystallographic analysis of the 〈110〉 and 〈111〉 vacancy-ordered structure of cubic δ-Bi2O3 obtained from electronic-structure calculations is presented. The ordering of vacancies leads to a doubling of the unit-cell that results in a 2×2×2 fluorite super-structure, with an associated reduction in its space group symmetry from Fm over(3, -) m to Fm over(3, -). The Bi atoms present inside the 〈111〉 vacancy-ordered oxygen sublattice have equal Bi-O bond lengths, whereas, those present inside the 〈110〉 vacancy-ordered oxygen sublattice have three different pairs of Bi-O bond lengths. The specific ionic displacements and electronic charge configurations also depend on the nature of vacancy ordering in the oxygen sub-lattice.
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