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

In this contribution the positron annihilation technique is used, because o f its specific sensitivity to vacancies, to investigate the effects of elec tron and proton irradiation on the lattice structure of ZnS and possible cl ustering mechanisms during isochronal annealing. Therefore, ZnS crystals we re irradiated either with 3 MeV protons to a fluence of 1.2 x 10(18) p/cm(2 ) or with 1 MeV electrons to a fluence of 1 x 10(18) e/cm(2) or 5 x 10(18) e/cm2, respectively. It was found that electron and proton irradiation caus es different changes in the positron annihilation characteristics. During i sochronal annealing these defects agglomerate to larger vacancy complexes o r even small voids. In both electron and proton irradiation several anneali ng stages can be observed, related to the annealing of variously sized vaca ncy complexes. Electron and proton irradiation leads to discoloration. (C) 1999 Elsevier Science B.V. All rights reserved.