MgO高温高压特性及相变的第一性原理研究  

First-principles study of high-pressure and high-temperature behaviors and phase transition of periclase

作　　者：赵福亮[1,2] 赵纪军 刘红[3] 吴迪[4] 刘雷[3] 郭永新[1] 

机构地区：[1]辽宁大学物理学院,沈阳110036 [2]大连理工大学高科技研究院,大连116024 [3]中国地震局地震预测研究所,北京100036 [4]沈阳航空工业学院,沈阳110034

出　　处：《原子与分子物理学报》2009年第1期57-62,共6页Journal of Atomic and Molecular Physics

基　　金：自然科学基金(40704012;40874039);新世纪优秀人才支持计划(NCET06-0281)

摘　　要：应用第一性原理密度泛函理论计算了MgO在零温(0K)下和0～200 GPa静水压范围内的晶体结构和弹性模量,以及B1、B4和B8相结构的MgO的声速随压力的变化.利用准简谐近似下的Debye模型,通过拟合三阶Birch-Murnaghan物态方程模拟了高温效应并对三个相在高温高压下的相稳定性做了研究.本工作的计算结果与前人的理论和实验结果符合较好,说明第一性原理结合准简谐Debye模型能够比较准确的模拟矿物如MgO在高温高压下的热力学性质.The high-pressure and/or high-temperature behavior and phase transition of periclase (MgO) were investigated by first principle calculations with density functional theory (DFT) ,and the quasi-harmonic Debye model in consideration of the temperature effect. At zero pressure and temperature,the calculated values of lattice parameters and elastic constants are well concordant with experimental data. We calculated the wave velocity in B1,B4 and B8 phases at 0 K with increasing pressure. We validated the reliability of Debye model in simulating the temperature effect and investigated the stability of the three phases in high pressure and temperature. Thus, the present results indicate that combination of first-principles and quasi-harmonic Debye model is a comparative efficient approach to simulate the partial behavior of minerals at high pressure and/or high temperature.

关 键 词：第一性原理 方镁石 相变 高压 

分 类 号：O521+.2[理学—高压高温物理]