On the equilibrium between the Si surface and the H-2 or D-2 gas phase

The thermometrical equilibrium between the surface of the silicon crystal a nd the gas phase of H-2- Or D-2-molecules is considered. The equilibrium co ncentrations of the H and D adatoms are calculated, It is shown that the di fference between the surface localized vibrations: of hydrogen and deuteriu m results in the difference of their surface concentrations. Due to this ef fect, the deuterium concentration turns out to be higher than the hydrogen concentration by an,order of magnitude.