TEM in situ investigation of dislocation mobility in II-VI semiconductor compound ZnS cathodoplastic effect and the Peierls mechanism

Abstract

Dislocation mobilities are studied in ZnS by in situ deformation in a transmission electron microscope, in a wide range of temperatures and electron beam intensities. The dislocation movement is smooth and continuous, which is the signature of lattice friction control. At variance with III-V compounds, there is only a weak difference between the velocity of screw, α and β dislocations. There is a strong enhancement of dislocation mobility under electron beam irradiation, and the characteristics of this effect (cathodoplastic effect) are reported: the dislocation glide is temperature dependent, the velocity of the moving segments being proportional to their length in all the investigated temperature and intensity ranges. All these results suggest that the dislocation behaviour under electronic excitation is still controlled by the Peierls mechanism.