CADMIUM SUBSTITUTION IN MIARGYRITE (AGSBS2) AND RELATED PHASES - AN EXPERIMENTAL RECONNAISSANCE

An experimental study of cadmium substitution into AgXS(2) phases (X = As, Bi, Sb) indicates significant amounts of cadmium can be incorpora ted in the structure by the mechanism 2Cd reversible arrow Ag + X. The limit of substitution of Cd in the high-temperature polymorph of miar gyrite, beta-AgSbS2 is 6.2 at.%, whereas the low-temperature polymorph , alpha-AgSbS2, can accommodate at least 12 at.% cadmium. Substitution of Cd into the cubic beta-AgSbS2 induces a small monoclinic distortio n and the unit cell becomes pseudo-cubic. The alpha reversible arrow b eta transition in Cd-substituted miargyrites is modified by the solute ions, with both a reduction of T-c and transition smearing evident. S imilar effects are also recorded in Cd-substituted AgAsS2 and AgBiS2.