高压物理学报2024，Vol.38Issue(3)：70-79,10.DOI:10.11858/gywlxb.20240765
<111>方向单轴应变下金刚石和硅的广义层错能
Generalized Stacking Fault Energies of Diamond and Silicon under<111>Uniaxial Loading
摘要
Abstract
The energy caused by atomic level shear in a crystal is called generalized fault energy(GSFE),This is an important material property for describing nanoscale plastic phenomena in crystalline materials,such as dislocation decomposition,nucleation,and twinning.During the shock loading process,the elastoplastic transition occurs after one-dimensional elastic strain,so the generalized stacking fault energy is of great significance in understanding the occurrence of plastic flow.Here,we calculate the generalized GSFE surface of glide(111)surface of silicon and diamond under uniaxial strain in[111]direction by using the first principles of density functional theory.Based on the translation symmetry of GSFE surface,we fit the GSFE surface expression obtained by Fourier series expansion and the generalized stacking fault energy curves for the[110](111)and[1 12](111)directions are given.With the increase of strain,the intrinsic fault energy(γI)and the unstable fault energy(γus)have obvious changes,and the ratio of the unstable stacking fault energy to the intrinsic stacking fault energy(γus/γI)decreases indicating that dislocations in crystals are not easily decomposed under uniaxial strain in the<111>direction.This result explains the results of dynamic experiments of dislocation evolution at four generations of light sources that the speed and strength of fault signals loaded along<111>direction are much lower than those loaded along<110>direction and<100>direction.关键词
广义层错能/第一性原理计算/冲击加载/位错Key words
generalized stacking fault energy/first principle calculations/shock loading/dislocation分类
数理科学引用本文复制引用
黄丽丽,彭丽,陈实,张红平,李牧..<111>方向单轴应变下金刚石和硅的广义层错能[J].高压物理学报,2024,38(3):70-79,10.基金项目
国家自然科学基金(12204317,11974321,11972330) （12204317,11974321,11972330）
