First-principles calculations are performed to examine the high-pressure behavior of the berlinite system GaAsO4. Structural properties of six possible GaAsO4 phases, berlinite, VCrO4, rutile, AlNbO4, BiSbO4 and a monoclinic structure with space group P21/m11, are investigated up to 25GPa. It is shown that between 1.4 and 2.3 GPa, a monoclinic AlNbO4-type structure is energetically favored, and beyond this range the favored structure is a rutile form. We also identify an unexpected metastable form of rutile structure (rutile-II) produced as a high-pressure modification of the VCrO4-type structure.
|Original language||English (US)|
|Number of pages||6|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Jan 1 1999|