Amorphous samples were prepared via the glow discharge of silane, and the kinetics of H exo-diffusion were studied by using conductivity, electron paramagnetic resonance, nuclear activation, and infra-red absorption methods. The results revealed the existence of two main stages of exo-diffusion. Below 500C, H evolution was controlled by a diffusion process which could be described by:

D (cm2/s) = 4.7 x 10-3 exp[-1.5(eV)/kT]

The H evolution at temperatures greater than 500C was controlled by a first-order process. The activation enthalpy and entropy were equal to 3.4eV and 7.8k, respectively.

K.Zellama, P.Germain, S.Squelard, B.Bourdon, J.Fontenille, R.Danielou: Physical Review B, 1981, 23[12], 6648-67