Lattice parameter and microhardness investigations on CdTe1-xSex

CdTe1-xSex anion mixed crystals have been grown from non-stoichiometric melts and by means of a modified vertical travelling-heater method. Selenium has been found to have an essentially higher affinity for cadmium than tellurium. The cubic phase (zincblende structure) exists in the composition range 0xCdSe0.45, the hexagonal phase (wurtzite structure) in the range 0.65xCdSe1. In order to compare the lattice parameters of the cubic and hexagonal modifications, the mean distances between next-neighbouring anions and cations, da-c, were calculated from the lattice parameters. The relation between da-c values and composition x roughly obeys Vegard's rule. By means of Vickers indentation microhardness measurements, the solid-solution hardening (SSH) behaviour was investigated for the first time and has been compared with the SSH of II–VI cation solid solutions. Regarding the hexagonal CdTe1-xSex modifications, one has to pay attention to the large anisotropy of microhardness depending on the surface orientation. © 1998 Kluwer Academic Publishers