The self-diffusion of Cd in CdS

Abstract

The self-diffusivity of Cd in CdS, D(Cd), has been measured by a radiotracer technique between 500 and 850 degrees C at the minimum total pressure (p_Cd^min) and saturated Cd pressure (p_Cd^sat) and also as a function of p_Cd at 675, 750 and 850 degrees C. Above 700 degrees C D(Cd, p_Cd^sat)=(0.058/sub //^*1.44)exp(-(1.85+or-0.03) eV/kT) cm² s^-1 and D(Cd, p_Cd^min)=(1.53/sub //^*3.17) exp(-(2.47+or-0.11)eV/kT) cm² s^-1, whereas below 700 degrees C D(Cd,p_Cd^sat)=(672/sub //^*16.3) exp(-(2.67+or-0.22) eV/kT) cm² s^-1 and D(Cd, p_Cd^min)=(7.6+or-2.8)*10^-14 cm² s^-1. Above 700 degrees C the results are satisfactorily explained in terms of a Cd_i^.. or a doubly ionised Cd_i-related donor and a (Cd_i^x Cd_i^.)pair or a Cd_s defect diffusion mechanism. Below 700 degrees C the situation is much less clear although there are indications of a V_Cd or V_Cd-related mechanism.