The perturbed γ-γ angular correlation spectroscopic method was used to study the diffusion and desorption of isolated 111In atoms which were adsorbed on the 7 x 7 (111) surface. Two different adsorption sites were found. The activation energy for migration to normal adsorption sites was deduced to be 0.72eV. The relative populations of the 2 adsorption sites changed at about 500K; suggesting an activation energy of 1.61eV for the process. The binding energy of the In atoms was estimated to be 1.93eV. The desorption behaviour depended strongly upon the In concentration in the low-coverage regime.

Binding and Mobility of Isolated Indium Atoms on Si(111)7×7. G.Krausch, T.Detzel, R.Fink, B.Luckscheiter, R.Platzer, U.Wöhrmann, G.Schatz: Physical Review Letters, 1992, 68[3], 377-80