Deformation characteristics and real structure around indents on {111}_A-surfaces of II–VI solid solutions

Abstract

The microhardness of II–VI compounds and their solid solutions has been measured at temperatures from 0.2 to 0.44T _m. Deformation effects around indents on {111}_A-surfaces have been studied by means of selective etching. Changes in the real structure, reflected in the hardness-temperature slope, are discussed in terms of different rate-controlling mechanisms, e.g. dislocation slipping and climbing, and of solid solution hardening effects. Deformation by indentation is characterized, for the investigated temperature range, by an activation energy ofQ≈0.1 eV in the case of (Cd, Zn) (Te, Se) and ofQ=0.12 ... 0.23 eV for Hg-containing compounds. A slightly different hardness between {111}_A- and {111}_B-faces occurs in Hg_0.32Cd_0.68Te at temperatures between 360 K and 500 K. Critical stresses for α-dislocation motion, derived from dislocation configurations around the indents, yield values ranging from 12.5 MPa at 295 K to 1.2 MPa at 500 K. Micro-twinning is one of the deformation modes of (Cd, Zn) (Te, Se) below 400 K.