Induced defects in ZnS by electron and proton irradiation and defect-annealing behavior

In this contribution the positron annihilation technique is used, because of its specific sensitivity to vacancies, to investigate the effects of electron and proton irradiation on the lattice structure of ZnS and possible clustering mechanisms during isochronal annealing. Therefore, ZnS crystals were irradiated either with 3 MeV protons to a fluence of 1.2×1018 p/cm2 or with 1 MeV electrons to a fluence of 1×1018 e/cm2 or 5×1018 e/cm2, respectively. It was found that electron and proton irradiation causes different changes in the positron annihilation characteristics. During isochronal annealing these defects agglomerate to larger vacancy complexes or even small voids. In both electron and proton irradiation several annealing stages can be observed, related to the annealing of variously sized vacancy complexes. Electron and proton irradiation leads to discoloration.