金属Cr的电子结构和物理性质

来源期刊：中南大学学报(自然科学版)2003年第3期

论文作者：邓永平 谢佑卿 刘心笔

文章页码：228 - 231

关键词：Cr;电子结构;晶体结构;晶格常数;结合能

Key words：Cr; electronic structure; crystalline structure; lattice constant; cohesive energy

摘    要：依据纯金属单原子理论(OA)确定了体心立方结构(bcc)Cr的电子结构为[Ar](3d_c)^3.32(3d_n)^2.26(4s_c)^0.25-(4s_f)^0.17,并对Cr的面心立方结构(fcc)和密排六方结构(hcp)初态特征晶体和初态液体的电子结构进行了研究.在此基础上,定性地解释了Cr的电子结构和晶体结构之间的关系:bcc→hcp→fcc结构的转变过程中,d_c电子逐渐减少(3.32→3.24→3.14),s_c电子逐渐增加(0.25→0.28→0.32),电子云分布的对称性逐渐增强而方向性逐渐减弱,故形成晶体时配位数逐渐增加的现象;并通过计算得到了bcc-Cr的势能曲线、弹性和热膨胀系数随温度的变化曲线.

Abstract: Using the One-Atom Theory (OA), the electronic structure of pure Cr metal with bcc structure was determined as follows: [Ar](3d_c)^3.32(3d_n)^2.26(4s_c)^0.25-(4s_f)^0.17. The electronic structure of this metal with hcp and fcc structure and liquid state was also studied. According to its electronic structure, the relationship between the electronic structure and crystalline structure was explained qualitatively: in the transformation process of bcc →hcp→fcc, d_c electrons decrease gradually(3.32→3.24→3.14)and s_c electrons increase gradually(0.25→0.28 →0.32), so the symmetry of the electrons distribution increases and the coordination number of the crystals increases gradually. The potential curve, elasticities and the temperature dependence of linear thermal expansion coefficient of bcc-Cr were calculated quantitatively.