Minár J, Perlov A, Ebert H, Hashizume H
Department Chemie, Physikalische Chemie, Universität München, Butenandstraße 5-13, Haus E-2.037, D-81337 München, Germany.
J Phys Condens Matter. 2005 Sep 21;17(37):5785-5794. doi: 10.1088/0953-8984/17/37/014.
To explain the remarkable oscillations observed in the x-ray magnetic circular dichroic absorption spectra from Gd/Cu multilayers at the Cu K edge, ab initio calculations have been made using the fully relativistic Korringa-Kohn-Rostoker formalism including the spin-orbit coupling. The result reproduces well the oscillatory profiles in the near-edge region, but the peaks and valleys do not correspond to those in the difference density of states [Formula: see text] for the unoccupied Cu 4p band above the Fermi level. We find small spin and orbital moments on the interfacial Cu sites, which decay towards the core of the Cu layer. Surprisingly, neither the spin nor the orbital moments die out on the Cu sites four atomic layers away from the Co interface. This extended polarization is ascribed to the hybridization of the Cu 4p and the Gd 5d states. The accuracy of the calculation is supported by the near-bulk spin and orbital moments found on the Gd sites away from the interface.
为了解释在Gd/Cu多层膜的Cu K边X射线磁圆二色吸收光谱中观察到的显著振荡，我们使用了包括自旋轨道耦合的全相对论性Korringa-Kohn-Rostoker形式进行了从头算。结果很好地再现了近边区域的振荡轮廓，但峰谷与费米能级以上未占据的Cu 4p能带的态密度差[公式：见正文]中的峰谷不对应。我们发现界面Cu位点上有小的自旋和轨道矩，它们向Cu层核心衰减。令人惊讶的是，在距Co界面四个原子层的Cu位点上，自旋和轨道矩都没有消失。这种扩展极化归因于Cu 4p和Gd 5d态的杂化。远离界面的Gd位点上的近体自旋和轨道矩支持了计算的准确性。
