摘要
采用密度泛函理论的超软赝势平面波方法,系统地研究了高压下AgMgF_(3)晶体的结构、力学、热力学和电子性质.研究表明,零温零压下AgMgF_(3)晶体的晶格常数、体弹模量均与文献值符合很好;不同压强下AgMgF_(3)晶体均表现出了良好的延展性,并随压强的增大而增大.根据立方形晶体力学稳定条件,预测出了立方形的AgMgF_(3)的相变点约为54.36 GPa.通过分析不同压强下立方形的AgMgF_(3)晶体的各项异性特性,发现其各项异性程度随着压强的增大而增大.利用准谐近似德拜模型,研究了AgMgF_(3)晶体热力学性质,包括体积、热容、热膨胀系数α、相对德拜温度与温度和压强的关系.同时,研究了不同压强下AgMgF_(3)晶体的电子态密度和能带结构,研究表明,AgMgF_(3)均保持为间接带隙半导体化合物,且带隙值整体呈现增大的趋势.相关研究为AgMgF_(3)晶体的进一步的实验及应用研究提供一定的理论指导.
Using the density functional theory and the ultrasoft pseudopotential plane-wave method,we systematically investigated the structure,mechanics,thermodynamics,and electronic properties of AgMgF_(3) crystal under high pressure.Our study reveals that the lattice constant and bulk modulus of AgMgF_(3) crystal at zero temperature and pressure are in good agreement with literature values.The crystal exhibits excellent ductility at various pressures,increasing with higher pressure.Based on the stability conditions of cubic crystal structures,we predict the phase transition point of cubic AgMgF_(3) to be approximately 54.36 GPa.Analysis of the anisotropic properties of cubic AgMgF_(3) crystal at different pressures shows an increasing level of anisotropy with increasing pressure.Using the quasi-harmonic Debye model,we investigate the thermodynamic properties of AgMgF_(3) crystal,including volume,heat capacity,thermal expansion coefficient α,and the relationship between the relative Debye temperature and temperature and pressure.Furthermore,we study the electronic density of states and band structure of AgMgF_(3) crystal at different pressures.Our findings indicate that AgMgF_(3) remains an indirect bandgap semiconductor,and the bandgap value shows an overall increasing trend with pressure.This research provides valuable theoretical guidance for further experimental and applied studies of AgMgF_(3) crystal.
作者
李梓宁
许楠林
肖循
陈艳
陈善俊
张伟斌
LI Zining;XU Nanin;XIAO Xun;CHEN Yan;CHEN Shanjun;ZHANG Weibin(School of Physics and Optoelectronic Engineering,Yangtze University,Jingzhou,Hubei 434023,China;School of Science,Wuhan University of Technology,Wuhan 430070,China;College of Physics and Electronics Information,Yunnan Normal University,Kunming 650500,China)
出处
《昆明理工大学学报（自然科学版）》
北大核心
2023年第5期28-37,共10页
Journal of Kunming University of Science and Technology(Natural Science)
基金
国家自然科学基金项目(52262042)
湖北省教育厅基金项目(Q20221310)。
关键词
AgMgF_(3)
弹性常数
相变
热力学性质
电子性质
AgMgF3
elastic constant
transition phase
thermodynamic properties
electronic properties
