Tracer diffusion of cu in CVD β-SiC

Tracer diffusion coefficients of Cu-67 and Cu-64 in CVD beta-Silicon carbide (beta-SiC) have been measured in the temperature range between 623 and 1373 K by use of a serial ion-beam Sputter-microsectioning technique. The temperature dependence of the diffusion coefficient D is expressed by D-Cu* = 8.2(-0.5)(+0.5) x 10(-16) exp(-41 +/- 1 kJ mol(-1)/RT) m(2) s(-1). The diffusion coefficient of Cu in beta-SiC is larger than those of Si and C by more than six orders of magnitude and those of Fe and Cr by one-three orders of magnitude. The activation energy for the diffusion of Cu is about one twentieth of that for the self-diffusion. The results suggest that an interstitial mechanism operates on the diffusion of Cu in beta-SiC. (C) 2007 Published by Elsevier Ltd.