%0 Journal Article
%T 钍基碳化物ThC的高压结构稳定性研究<br>Structural stability of ThC under high pressure
%A 胡翠娥
%A 王艳
%A 邓礼松
%J 原子与分子物理学报
%D 2018
%X 钍基碳化物ThC是重要的核材料，基于第一性原理计算，我们研究了ThC的结构稳定性及相变. 声子色散曲线表明基态结构的晶格能够稳定到42 GPa附近, 当压力继续升高时虚频的出现表明了动力学的不稳定. 经比较基态Fm-3m及高压相Pnma结构的自由能, 发现零温下,相变压力为22.4 GP，符合声子色散的结果, 同时预测了两种结构的相变边界.<br>The phase transition and structure stability of binary compounds of actinide metal ThC have always attracted much attention of the experimental and theoretical investigators. The stable phase of ThC at room condition is rock salt structure, but the high pressure phase transitions may be possible. Under compression, we captured a large softening around the X point. When the pressure is raised to 42 GPa, the frequencies around the T point in transverse acoustical branches become imaginary, indicating a structural instability. Within the quasi-harmonic approximation, we predicted the high pressure phase boundary.
%K 锕系元素 高压 相变 第一性原理&lt
%K br&gt
%K Actinide metals high pressure phase transition first principle
%U http://jamp.ijournals.cn/jamp/ch/reader/view_abstract.aspx?file_no=18056&flag=1