The tracer diffusivity of radioactive 110Ag on thin epitaxial layers was determined. The layers were prepared by vacuum deposition onto mica substrates. This resulted in epitaxial layers which had a <111> surface, and thicknesses which ranged from 0.1 to above 1μ. At each temperature, diffusion over the layer surface was monitored by means of autoradiography. The results for various layers were then extrapolated to zero thickness to give a surface diffusion coefficient (table 2). This made it possible to determine the surface self-diffusion coefficient without the need to assume an arbitrary surface layer thickness. The activation energy, at temperatures ranging from 95 to 160C, was 0.34eV.

Y.T.Tan, W.Perkett, R.J.Powell: Journal of Applied Physics, 1971, 42[12], 4752-7

Table 2

Surface Self-Diffusion of 110Ag on AgBr