High-pressure behavior of raman modes in cugase2

Abstract

The pressure dependence of the Raman modes of CuGaSe2have been investigated up to 20 GPa in a gasketed diamond-anvil cell using neon gas as pressure transmitting medium. An assignment of the symmetry of the zone-center modes is proposed on the basis of their pressure dependence as compared to that of the corresponding modes in zinc-blendeZnSe. The effect of pressure on the phonon frequencies is discussed in terms of the Grneisen parameters. From changesin the Raman spectra of the samples under pressure, a first-order phase transition, from the chalcopyrite to the disorderrocksalt structure, was observed at 14 GPa. © 1993 The Japan Society of Applied Physics.