STRUCTURAL CHARACTERIZATION OF THE CINNABAR PHASE IN ZnSe_xTe_1-x ALLOYS

Abstract

We report energy dispersive x-ray diffraction experiments carried out in the Te rich side of ZnSe_xTe_1-x alloys with the aim of characterizing the cinnabar phase. In the samples studied (x =0.55, 0.2, 0.1 and 0.0) the cinnabar phase is observed both in the upstroke and downstroke, between either the zincblende and rocksalt phases (x =0.55, 0.2), or between the zincblende and Cmcm phases (x =0.1, 0.0). In ZnSe_0.2Te_0.8 the rocksalt phase is transformed to the Cmcm phase if additional pressure is applied. The dependence of the cinnabar's lattice parameters with composition is given by a=4.062 — 0.262x and c =9.434 — 0.575x.

Keywords:

• High pressure
• X-ray diffraction
• II-VI compounds
• Phase transition
• Cinnabar