On the direct measurement of diffusion at temperatures less than 0.5 T_m

The important microsectioning techniques developed in the last decade for the direct measurement if diffusion at low temperatures (<0.5 Tm) are briefly reviewed and critically discussed. A powerful variant of these techniques is material removal by r.f. backscattering in an Ar glow discharge which enables tracer profiling to be carried out in steps of about 30 Å or more directly and expeditiously and also independently of the nature of material. The relative merits of the various techniques described are discussed by examining the quality of the recently available low temperature diffusion data for Au. © 1975.