An Ultrasonic Identification of Diffusion Mechanisms in CdS

Abstract

Abstmt-An ultrasonic method of measuring diffusion coefficients of compensating impurities in cadmium sulphide (CdS) is described. From the results, activation energies for the diffusion of Cu, Ag, and Au in single crystal CdS were found to be 1.05, 1.48, and 2.10 eV, respectively, with an expected error of *S percent. The linearity of the Arrhenius plots over many orders of magnitude indicate one dominent diffusion mechanism. A theoretical relationship is established between the mass of the diffusing atom and the activation energy of the diffusion process. From the relationship the mean diffusion jump size is calculated to be 0.26 nm f 12 percent. This result is shown to be consistent with an interstitial substitutional mechanism.