Abstract

The spin-polarized electronic structure, magnetic moments, and spectra of optical conductivity of the ternary ErSn_1.1Ge_0.9 and TmSn_1.1Ge_0.9 compounds have been calculated within the GGA+U method, taking into account strong electron correlations in the 4f-shell of Er and Tm, as well as non-stoichiometry of compositions. The calculation results pointed to antiferromagnetic ordering for both intermetallics with effective magnetic moments that precisely reproduce the published experimental values. Optical properties of these compounds were measured using the ellipsometric method in the energy range of 0.078–5.64 eV. It has been shown that the main peculiarities of experimental curves are described by calculated densities of electronic states. The good agreement of magnetic moments and interband optical conductivities, which are calculated from first principles, with the experimental data indicates the importance of accounting for the strong electron correlations and non-stoichiometry of compositions in calculations of electronic structure of the RSn_1.1Ge_0.9-type compounds containing heavy rare-earth metals.

中文翻译：

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ErSn 1.1 Ge 0.9和TmSn 1.1 Ge 0.9化合物的电子态和光谱

摘要

考虑到4 f中的强电子相关性，在GGA + U方法中已计算出三元ErSn _1.1 Ge _0.9和TmSn _1.1 Ge _0.9化合物的自旋极化电子结构，磁矩和光导谱。和Tm的壳，以及组成的非化学计量。计算结果表明，两种金属间化合物具有有效的磁矩的反铁磁有序，可以精确地再现已发布的实验值。这些化合物的光学性质是通过椭圆偏振法在0.078–5.64 eV的能量范围内测量的。已经表明，实验曲线的主要特征是通过计算的电子态密度来描述的。由第一性原理计算得出的磁矩和带间光导率与实验数据的良好一致性表明，在计算RSn _1.1 Ge的电子结构时，考虑组分的强电子相关性和非化学计量比非常重要含重稀土金属的_0.9型化合物。