Symmetry of Valence States of Heusler Compounds Explored by Linear Dichroism in Hard-X-Ray Photoelectron Spectroscopy
Symmetry of Valence States of Heusler Compounds Explored by Linear Dichroism in Hard-X-Ray Photoelectron Spectroscopy
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DOI：
10.1103/physrevlett.107.036402
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发表时间：
2011-07-12
影响因子：
8.6
通讯作者：
Kobayashi, Keisuke
中科院分区：
文献类型：
--
作者：
Ouardi, Siham;Fecher, Gerhard H.;Kobayashi, Keisuke
本文报道了Heusler化合物NiTi0.9Sc0.1Sn和NiMnSb的价带角分辨光电子谱的线性二色性。高分辨率光电子能谱进行了与激发能量为h nu = 7.938 keV。使用真空金刚石相位延迟器改变光子的线偏振。价带谱显示出这些化合物的电子结构的第一性原理计算预期的典型结构。在这两种材料的价带中发现了明显的线性二向色性，这允许对贡献态进行对称性分析。光谱中的差异被发现是由依赖于角不对称性参数，这些甚至发生在多晶样品没有优先结晶取向。
This study reports on the linear dichroism in angular-resolved photoemission from the valence band of the Heusler compounds NiTi0.9Sc0.1Sn and NiMnSb. High-resolution photoelectron spectroscopy was performed with an excitation energy of h nu = 7.938 keV. The linear polarization of the photons was changed using an in-vacuum diamond phase retarder. The valence band spectra exhibit the typical structure expected from first-principles calculations of the electronic structure of these compounds. Noticeable linear dichroism is found in the valence band of both materials, and this allows for a symmetry analysis of the contributing states. The differences in the spectra are found to be caused by symmetry-dependent angular asymmetry parameters, and these occur even in polycrystalline samples without preferential crystallographic orientation.