Abstract
A new high-pressure phase, silicon phosphate hydroxide, was prepared at 8.3±0.5GPa and 1000°C in >98% purity. From X-ray diffraction on a pseudo-merohedrally twinned crystal, it was found that SiPO4(OH) crystallizes in a monoclinic cell with space group P21/n (No. 14), a=6.8446(11)Å,b=6.8683(13)Å,c=6.8446(11)Å,β=119.77(1) °, and Z=4. The refinement gave a conventional Robs of 0.0320 and wRobs of 0.0864 for the overlapped data from both twin components. In the structure, SiO6 octahedra form chains along [101], with PO4 tetrahedra alternating along the chain in the b-direction. The parallel chains link up with tetrahedral corners from other chains to form a 3-dimensional network. SiPO4(OH) belongs to a structural family that includes HgSeO4·H2O. It is also related to the SbOPO4 structure by a small distortion that lowers the symmetry from C2/c in SbOPO4 to P21/c(P21/n) in SiPO4(OH).
Original language | English (US) |
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Pages (from-to) | 2594-2601 |
Number of pages | 8 |
Journal | Journal of Solid State Chemistry |
Volume | 178 |
Issue number | 9 |
DOIs | |
State | Published - Sep 1 2005 |
Keywords
- High-pressure synthesis
- Pseudo-merohedral twinning
- Silicon phosphates
- Six-coordinated silicon
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry