Dislocations and Glide in Lead Sulfide as a Function of Deviations from Stoichiometry and Doping Additions

Abstract

Point defects induced in PbS by slight deviations in chemical composition about the stoichiometric ratio were shown in a qualitative experimental study to affect dislocation density and strength. A very small but reproducible increase in dislocation density was observed by an etch‐pit method in single crystals of PbS and in silver‐doped PbS having excess sulfur or excess lead as compared with the stoichiometric composition. With a prismatic punching technique to obtain a measure of the yield strength, a slight increase in strength was found to correlate with an increase in point defect concentration in PbS. An etch‐pit and slip‐line analysis of glide in stoichiometric PbS verified the single primary glide system {100}〈110〉.