高压下Fe_(2)S的相变及热力学性质的第一性原理研究  

First-principles study on the phase transition and thermodynamic properties of Fe_(2)S under high pressure

作　　者：余柏树 焦亩鑫 杨学楠 曾召益[1] YU Bai-Shu;JIAO Mu-Xin;YANG Xue-Nan;ZENG Zhao-Yi(College of Physics and Electronic Engineering,Chongqing Normal University,Chongqing 401331,China)

机构地区：[1]重庆师范大学物理与电子工程学院,重庆401331

出　　处：《原子与分子物理学报》2025年第5期102-107,共6页Journal of Atomic and Molecular Physics

基　　金：重庆市自然科学基金(cstc2020jcyj-msxmX0616)。

摘　　要：本文采用基于密度泛函理论的赝势平面波方法研究了高压下Fe_(2)S的结构相变、弹性性质和热力学性质.计算表明,当压强增加到124±10 GPa时,Fe_(2)S(Co_(2)P型)的晶格常数发生了突变,轴向比c/a从1.20跃迁到1.35,向C37结构(Co_(2)Si型)转变.弹性模量的计算结果也证实了Fe_(2)S的这一结构相变.根据弹性模量,获得了高压下Fe_(2)S的声速,相对于纯Fe,S元素提升了纵波声速.通过准谐德拜模型预测了200 GPa,2000 K范围内Fe_(2)S的热力学性质.The structural phase transition,elastic,and thermodynamic properties of Fe_(2)S under high pressure are investigated by using the spin-polarized generalized gradient approximation within density functional theory.It is found that there is a phase transition of Fe_(2)S from C23 structure(Co_(2)P-type)to C37 structure(Co_(2)Si-type)at 124±10 GPa,and the axial ratio c/a jumps from 1.20 to 1.35.The calculated elastic modulus also confirms this structural phase transition.The results of sound velocities of Fe_(2)S show that the S element increases the longitudinal sound velocities compared to pure Fe.

关 键 词：相变 弹性性质 热力学性质 第一性原理 

分 类 号：O641[理学—物理化学]