Dynamical coherent potential approximation approach to excitation spectra in 3d transition metals
Dynamical coherent potential approximation approach to excitation spectra in 3d transition metals
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3d 过渡金属激发光谱的动态相干势近似方法
DOI：
10.1103/physrevb.81.245133
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
and T.Tamashiro
中科院分区：
文献类型：
--
作者：
Y. Kakehashi;M.A.R. Patoary;and T.Tamashiro
通过考虑高阶动力学修正，利用渐近近似，进一步发展了电子关联的第一性原理动力学相干势近似。本文应用这一理论研究了从Sc到Cu的过渡金属在有限温度下激发光谱的系统变化。结果表明，动力学效应阻尼的状态密度（DOS）由局域密度近似的密度泛函理论的主峰，减少由于热自旋涨落的带展宽，创建Mott-Hubbard型带的情况下，面心立方Mn和面心立方Fe，并创建一个小驼峰对应的“6 eV”的卫星的情况下的Co，Ni和Cu。计算DOS解释的X射线光电子能谱数据以及韧致辐射等色线光谱数据。此外，发现屏蔽效应对磁性过渡金属的交换能参数的影响对于理解磁性过渡金属的光谱具有重要意义。
First-principles dynamical coherent-potential approximation for electron correlations has been developed further by taking into account higher-order dynamical corrections with use of the asymptotic approximation. The theory is applied to the investigations of a systematic change in excitation spectra intransition metals from Sc to Cu at finite temperatures. It is shown that the dynamical effects damp main peaks in the densities of states (DOSs) obtained by the local-density approximation to the density-functional theory, reduce the band broadening due to thermal spin fluctuations, create the Mott-Hubbard-type bands in the case of fcc Mn and fcc Fe, and create a small hump corresponding to the “6 eV” satellite in the case of Co, Ni, and Cu. Calculated DOS explain the x-ray photoelectron spectroscopy data as well as the bremsstrahlung isochromat spectroscopy data. Moreover, it is found that screening effects on the exchange energy parameters are significant for understanding the spectra in magnetic transition metals.