Direct probing of temperature-independent bulk half-metallicity in Co2MnSi by spin-resolved hard x-ray photoemission
Direct probing of temperature-independent bulk half-metallicity in Co2MnSi by spin-resolved hard x-ray photoemission
复制标题
通过自旋分辨硬 X 射线光电子直接探测 Co2MnSi 中与温度无关的块体半金属性
DOI：
10.1103/physrevb.106.075101
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发表时间：
2022
影响因子：
3.7
通讯作者：
Sakuraba Yuya
中科院分区：
文献类型：
--
作者：
Ueda Shigenori;Miura Yoshio;Fujita Yuichi;Sakuraba Yuya
我们已经进行了体敏自旋分辨硬X射线光电子能谱（HAXPES）直接澄清的自旋相关的价带电子态和自旋极化的orderedas一个预测的半金属。自旋分辨的价带HAXPES谱清楚地显示了在21和300 K的温度下，埋在MgO（2 nm）层下的30 nm厚的薄膜的体区域中的多数和少数自旋态的差异。正如预期的半金属性，我们发现，大多数（少数）自旋谱显示金属费米边缘（带隙），导致在费米能级附近的21 K的温度下的高自旋极化的90%。自旋分辨的HAXPES实验表明，在300 K以下，体区的半金属度与温度无关。实验还揭示了多数自旋谱形状和少数自旋态价带顶随温度的变化。通过将实验结果与无序局域矩方法在有限温度下的第一性原理计算结果进行比较，我们认为，随温度变化的多数自旋和少数自旋HAXPES谱的微小变化主要是由随温度变化的共电子态引起的.还表明，导带最低的少数自旋态位于足够的费米能级以上的温度高达300 K。
We have performed the bulk-sensitive spin-resolved hard x-ray photoelectron spectroscopy (HAXPES) to directly clarify the spin-dependent valence band electronic states and spin polarization of-orderedas a predicted half-metal. The spin-resolved valence band HAXPES spectra clearly exhibited the difference in the majority and minority spin states in the bulk region of a 30-nm-thickthin film buried under a MgO(2 nm) layer at both temperatures of 21 and 300 K. As expected from the half-metallicity in, we found that the majority (minority) spin spectrum shows a metallic Fermi edge (a band gap), leading the high spin polarization of ∼90% at around the Fermi level at a temperature of 21 K. The spin-resolved HAXPES experiments revealed that the half-metallicity ofin the bulk region is independent on the temperature up to 300 K. The experiments also revealed the slight changes in the majority spin spectral shapes and the shift of the valence band maximum of the minority spin states with temperature. By comparing the experimental results with the first-principles calculations at a finite temperature obtained by the disordered local moment method, it is suggested that the slight changes in the majority and minority spin HAXPES spectra ofwith temperature is mainly caused by the temperature-dependent Coelectronic states. It is also suggested that the conduction band minimum of the minority spin states is located sufficiently above the Fermi level at temperature up to 300 K.