岩塩型結晶におけるb=1/2<110>刃状転位の構造とエネルギーに関する第一原理解析

抄録

Alkali halide crystals having the rock-salt crystal structure are generally brittle at low temperatures, but AgCl with the same structure is much more ductile than the other alkali halide crystals. Such a difference cannot be explained from a simple ionic picture of interatomic bonding, and thus should be closely related to the atomic structures at the dislocation cores. In this study, atomic structures and core energies of the two symmetric core configuration of edge dislocations for the slip system of {110}<110> in NaCl and AgCl were investigated in a first principles manner. The two symmetric atomic configurations were found to have almost equal dislocation core energies. It was found that the dislocation core structure in AgCl had lower core energy than that in NaCl, resulting from unique electronic structure at dislocation core in AgCl.