Structural characterization of a new high-pressure phase of GaAsO4.
Acta Crystallogr B
; 62(Pt 6): 1019-24, 2006 Dec.
Article
em En
| MEDLINE
| ID: mdl-17108655
ABSTRACT
As in SiO2 which, at high pressures, undergoes the alpha-quartz-->stishovite transition, GaAsO4 transforms into a dirutile structure at 9 GPa and 1173 K. In 2002, a new GaAsO4 polymorph was found by quenching the compound from 6 GPa and 1273 K to ambient conditions. The powder diagram was indexed on the basis of a hexagonal cell (a=8.2033, c=4.3941 A, V=256.08 A3), but the structure did not correspond to any known structure of other AXO4 compounds. We report here the ab initio crystal structure determination of this hexagonal polymorph from powder data. The new phase is isostructural to beta-MnSb2O6 and it can be described as a lacunary derivative of NiAs with half the octahedral sites being vacant, but it also contains fragments of the rutile-like structure.
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Base de dados:
MEDLINE
Assunto principal:
Arseniatos
/
Gálio
Tipo de estudo:
Diagnostic_studies
Idioma:
En
Ano de publicação:
2006
Tipo de documento:
Article