高压物理学报2025，Vol.39Issue(2)：21-30,10.DOI:10.11858/gywlxb.20240864
典型碱金属卤化物高压相变的第一性原理研究
First-Principles Investigation of the High-Pressure Phase Transition in Representative Alkali Metal Halides
摘要
Abstract
Utilizing first-principles calculations based on density functional theory,this study investigates the geometric,electronic,and mechanical properties of NaCl,KCl,and KBr crystals in phaseⅠand phaseⅡstructures under varying pressures.The relationships between these properties and the phase transition points are explored.Additionally,the Gibbs free energy method was employed to judge the phase transition points of NaCl,KCl,and KBr crystals.The results show that in the phaseⅠstructure of NaCl,the band gap value increases with pressure from 0 to 30 GPa.However,in the range of 30-50 GPa,the band gap value decreases,indicating that 30 GPa is the phase transition point for NaCl phaseⅠ.This suggests that pressure-induced changes in electronic structure can be indicative of metal halide phase transition points to some extent.However,pressure-induced alterations in crystal structure,phonon spectrum,and mechanical stability cannot reliably indicate alkali metal halide phase transition points.Furthermore,the phase transition points for NaCl,KCl and KBr calculated by Gibbs free energy method are 22.26,3.47 and 3.11 GPa,respectively.关键词
碱金属卤化物/相变/第一性原理/高压/带隙/吉布斯自由能Key words
alkali halide/phase transition/first-principles/high pressure/band gap/Gibbs free energy分类
数理科学引用本文复制引用
刘雨诗,章龙,李文广,刘其军,刘正堂,刘福生..典型碱金属卤化物高压相变的第一性原理研究[J].高压物理学报,2025,39(2):21-30,10.基金项目
国家自然科学基金(12072299) （12072299）
中央高校基本科研业务费专项资金(2682024GF019) （2682024GF019）
