Formation of dislocation loops and voids in electron irradiated zinc selenide single crystals

Abstract

The formation of small dislocation loops in size of 2.5 - 45 nm and a density of 1.4·1011 cm−2, as well as voids in size ≤10 nm in ZnS crystals were found by the transmission electron microscopy method (TEM). Samples were examined and irradiated in situ in a JEOL 4000EX-II electron microscope operated at energy of 400 keV and intensity of (1 - 4)·1019 e/cm2·s. Fine particles of a new phase in size ≤10 nm are formed also. These features can be identified from an analysis of moiré fringe contrast as phase of ZnO2. Similar defects in single crystals of ZnS formed in situ after irradiation in a transmission electron microscope JEM-100CX operated at energy of 100 keV and intensity of 3,5·1017 e/cm2·s. It was found that the formation of structural defects in ZnS under electron irradiation with above-threshold energy of defect formation (400 keV) is similar to the formation of structural defects in these crystals under electron irradiation with sub-threshold defect formation energy (100 keV).