CAJ | 학술논문

基于密度泛函理论的第一性原理计算获得了α-Ti2Zr的晶体结构、弹性常数、德拜温度和电子分布情况,研究了它们与压力的关系.计算得到的晶体结构参数与实验值一致.运用有限应变方法计算得到了α-Ti2Zr的体积模量B、剪切模量G、杨氏模量E和泊松比σ. B和E的零压值分别为101.2和35.6 GPa. G/B的值较小,并且随着压力的增加而减小,表明α-Ti2Zr具有优异的延展性.基于弹性常数得到平均声速,从而获得了德拜温度Θ=321.7 K.通过解Christoffel方程获得的压缩波和剪切波数据揭示α-Ti2Zr具有较强的各向异性.此外,压力诱导电子从s轨道到d轨道的转移说明在一定压力下α-Ti2Zr将转变为β相.
기우밀도범함이론적제일성원리계산획득료α-Ti2Zr적정체결구、탄성상수、덕배온도화전자분포정황,연구료타문여압력적관계.계산득도적정체결구삼수여실험치일치.운용유한응변방법계산득도료α-Ti2Zr적체적모량B、전절모량G、양씨모량E화박송비σ. B화E적령압치분별위101.2화35.6 GPa. G/B적치교소,병차수착압력적증가이감소,표명α-Ti2Zr구유우이적연전성.기우탄성상수득도평균성속,종이획득료덕배온도Θ=321.7 K.통과해Christoffel방정획득적압축파화전절파수거게시α-Ti2Zr구유교강적각향이성.차외,압력유도전자종s궤도도d궤도적전이설명재일정압력하α-Ti2Zr장전변위β상.
The structure, elastic constant, Debey temperature and electron distribution ofα-Ti2Zr under high pressure are presented by using first-principles pseudopotential method based on density functional theory in this paper. The calculated structural parameters at zero pressure are in agreement with experimental values. The elastic constants and their pressure dependence are calculated using the static finite strain technique. We obtain the bulk modulus, Young’s modulus and Poisson’s ratio forα-Ti2Zr. The G and B at zero pressure are 101.2 and 35.6 GPa, respectively. The G/B value is relatively small and decreases with pressure increasing, showing that theα-Ti2Zr is rather ductile. The Debye temperatureΘ =321.7 K is obtained by the average sound velocity based on elastic constants. We investigate anisotropies of the compressional wave and two shear waves. The acoustic velocities are obtained from elastic constants by solving Christoffel equation. The results indicate the strong anisotropy forα-Ti2Zr. Moreover, the pressure dependence of s→d electron transfer indicates thatβ-Ti2Zr will occur under high pressure.