Fe的结构与物性及其压力效应的第一性原理计算  

First-principles calculations of structures,properties and high pressures effects of Fe

作　　者：孙博[1] 刘绍军[1] 段素青[2] 祝文军[3] 

机构地区：[1]北京师范大学物理系,北京100875 [2]北京应用物理与计算数学研究所,北京100088 [3]中国工程物理研究院流体物理研究所冲击波物理与爆轰物理国防重点实验室,绵阳621900

出　　处：《物理学报》2007年第3期1598-1602,共5页Acta Physica Sinica

基　　金：国家自然科学基金委员会-中国工程物理研究院联合基金(批准号:10576004);国家自然科学基金(批准号:60471034)资助的课题.~~

摘　　要：采用基于密度泛函理论的平面波赝势方法,计算了Fe的几种不同晶体结构的总能量曲线,对HCP结构下晶体结构参数c/a随压强的变化关系做计算分析.能量计算精度取为0.01eV/atom.计算得出:1)零温下Fe从bcc到hcp结构的相变压强约为15GPa,与实验结果相一致;2)压强的升高会导致Fe的磁矩减小,最终破坏Fe的磁性;3)压强升高引起hcp晶体结构参数c/a缓慢增大,而在地核压强(135—360GPa)范围内,c/a取常量约1.59能够满足计算精度的要求.In this paper, we performed first-principles calculations for iron with different crystal structures based on density-function theory, employing the pseudopotentional and plane-wave method. We set the computational precision of energy to 0.01 eV/atom and made total-energy calculations. The calculated results show that： 1 ） The bcc iron undergoes a pressure-induced phase transform to hcp structure at about 15 GPa, which is in good-agreement with the experimental values; 2） The magnetic moment decreases with increasing pressure, which demonstrates that the high pressures will destroy the magnetism of iron; 3） The ratio of lattice parameters of hcp structure, c/a, will slowly increase with the pressure increasing. When set to a constant about 1.59, the c/a value can give the energy computation precision of 0.01 eV/atom under the pressures in the earth core.

关 键 词：第一性原理计算 压力效应 FE 结构 物性 

分 类 号：O521.2[理学—高压高温物理]