Abstract
Single crystals of the SrGeO3 (strontium germanium trioxide) high-pressure phase have been synthesized successfully at 6 GPa and 1223 K. The compound crystallizes with the ideal cubic perovskite-type structure (space group Pm3m), which consists of a network of corner-linked regular GeO6 octahedra (point-group symmetry m3m), with the larger Sr atoms located at the centers of cavities in the form of SrO12 cuboctahedra (point-group symmetry m3m) in the network. The degrees of covalencies included in the Sr - O and the Ge - O bonds calculated from bond valences are 20.4 and 48.9%, respectively. Thus, the Ge - O bond of the GeO6 octahedron in the SrGeO3 perovskite has a strong covalency, comparable to those of the Si - O bonds of the SiO4 tetrahedra in silicates with about 50% covalency. The thermal vibrations of the O atoms in the title compound are remarkably suppressed in the directions of the Ge - O bonds. This anisotropy ranks among the largest observed in stoichiometric cubic perovskites.
Original language | English |
---|---|
Pages (from-to) | 502-504 |
Number of pages | 3 |
Journal | Acta Crystallographica Section E: Structure Reports Online |
Volume | 71 |
Issue number | 5 |
DOIs | |
Publication status | Published - 2015 May 1 |
Keywords
- Crystal structure
- High-pressure phase
- Perovskite
- Strontium germanate
ASJC Scopus subject areas
- Chemistry(all)
- Materials Science(all)
- Condensed Matter Physics