Volume 40, Number 5, December I 1997
|Page(s)||533 - 538|
|Section||Condensed matter: structure, thermal and mechanical properties|
|Published online||01 September 2002|
A combined XAS and XRD study of the high-pressure behaviour of GaAsO4 berlinite
Laboratoire des Sciences de la Terre,
École Normale Supérieure de Lyon
46, allée d'Italie 69364 Lyon Cedex 07, France
2 Materials Research Group in High Pressure Synthesis, Department of Chemistry and Biochemistry, Arizona State University - Tempe, AZ 85287, USA
3 Physique des Milieux Condensés, Université Pierre et Marie Curie, B77 4, place Jussieu 75252 Paris Cedex 05, France
Accepted: 20 October 1997
Combined X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) ex peri ments have been carried out on α- (berlinite structure) at high pressure and room temperature. XAS measurements indicate four-fold to six-fold coordination changes for both cations. The two local coordination transformations occur at different pressure rates but appear to be coupled. A reversible transition to a high-pressure crystalline form occurs around 8 GPa. At a pressure of about 12 GPa, the system mainly consists of octahedral gallium atoms and a mixture of arsenic in four-fold and six-fold coordinations. A second transition to a highly disordered material with both cations in six-fold coordination occurs at higher pressures and is irreversible.
PACS: 62.50.+p – High-pressure and shock-wave effects in solids and liquids / 61.10.-i – X-ray diffraction and scattering / 61.10.Ht – X-ray absorption spectroscopy: EXAFS, NEXAFS, XANES, etc
© EDP Sciences, 1997
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.