高压下钒的结构相变研究  

Study on Structure Phase Transition of Vanadium under High Pressure

作　　者：刘海平[1] 曾祥华[1] 胡永金[1] 张萱[1] 

机构地区：[1]扬州大学物理科学与技术学院,江苏扬州225002

出　　处：《原子核物理评论》2009年第1期59-63,共5页Nuclear Physics Review

基　　金：江苏省科技厅资助项目(BG2007026)~~

摘　　要：运用密度泛函理论研究了钒(Vanadium)在高压下的结构相变。通过对体心立方(bcc)结构的钒在不同压强下剪切弹性系数C44的计算,发现当压强约95 GPa时C44<0,说明体心立方结构的钒在此条件下是不稳定的。进一步计算分析得到钒在高压下发生了从体心立方到菱面体(Rhom-bohedral)的结构相变,相变压强约70 GPa,这一结果与最近的实验结果符合。还首次发现当压强约380 GPa时,将会发生菱面体到体心立方的结构相变,这有待实验的验证。We have studied the structure phase transition of Vanadium under high pressures by density function theory. A mechanical instability in the shear elastic constant （C44） has been found for body-centred cubic（bcc） Vanadium at about 95 GPa, which indicates the existence of the structural transition. By calculation and analysis, we found that there was a bcc-rhombohedral structure transition at the 70 GPa, which is consistent with the experiment data. Our calculations also firstly gave that there was a rhombohedral-bcc structure transition at about 380 GPa, which needs to be verified by the experiment.

关 键 词：密度泛函理论 高压 剪切弹性系数 结构相变 

分 类 号：O521.23[理学—高压高温物理]