Electron momentum distribution and spin density of ferromagnetic iron studied by spin-polarised positron annihilation
Electron momentum distribution and spin density of ferromagnetic iron studied by spin-polarised positron annihilation
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自旋极化正电子湮灭研究铁磁铁的电子动量分布和自旋密度
DOI：
10.1088/0305-4608/18/9/014
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
M. Weller
中科院分区：
文献类型：
--
作者：
P. Genoud;Ashutosh Kumar Singh;A. Manuel;T. Jarlborg;E. Walker;M. Peter;M. Weller
作者报告了首次利用极化正电子湮灭辐射的二维角相关性对铁磁铁中的费米表面拓扑、电子动量密度和自旋动量密度进行的研究。独立粒子模型中的计算是通过自洽线性松饼罐轨道法获得的。实验与计算的比较显示出明显的差异，这是由于电子-电子和电子-正电子关联效应造成的。实验分布分析表明，与自洽的计算结果相比，少数第三能带的大N中心空穴袋并不存在。已进行参数化能带结构计算以解释电子-电子相关效应。与自洽分布相比，此过程产生的分布与实验更加一致。电子-正电子关联效应的性质再次被发现与 Sing 等人观察到的相似。对于镍。这证实了局域 d 电子的正负电子相关效应的系统趋势。相对自旋动量密度分布的正确描述需要对多数电子带和少数电子带采用不同的增强因子。
The authors report the first study of the Fermi surface topology, electron momentum density and spin momentum density in ferromagnetic iron using two-dimensional angular correlation of polarised positron annihilation radiation. A calculation made in the independent-particle model was obtained from the self-consistent linear muffin-tin orbital method. Comparison between experiment and calculation reveals marked discrepancies which are due to both electron-electron and electron-positron correlation effects. Analysis of experimental distributions shows that the large N-centred hole pocket of minority third band does not exist in contrast with the self-consistent calculation results. A parametrised band-structure calculation has been performed to account for the electron-electron correlation effects. Distributions resulting from this procedure were in better agreement with experiment than the self-consistent ones. Once again the nature of electron-positron correlation effects is found to resemble those observed by Sing et al. for nickel. This confirms the systematic trends of electron-positron correlation effects for localised d electrons. The correct description of the relative spin momentum density distribution requires different enhancement factors for majority and minority electron bands.