Interactions between this group-VI element and fast-diffusing impurities (Cr, Fe, Mn) were studied. Infra-red absorption, electron spin resonance, and neutron activation studies showed that the group-VI element effectively interacted with each other or with the fast-diffusing impurities. It was found that, for each pairing of a group-VI element with a fast-diffusing impurity, there was a certain annealing temperature at which they interacted most efficiently. A definite correlation was established between this annealing temperature and the thermodynamic Gibbs free energy (at 298K) of the corresponding compounds. This correlation suggested that the interaction process mainly involved the formation of electrically neutral chemically bonded complexes by substitutional group-VI element centers and interstitial fast-diffusant centers.

M.K.Bakhadirkhanov, S.I.Askarov, N.Norkulov: Physica Status Solidi A, 1994, 142[2], 339-46