Characterization of d and f Electronic States in RSn_1.1Ge_0.9 (R = Gd, Tb) Compounds by Optical Spectroscopy and Electronic‐Structure Calculations

Abstract

This paper presents the results of investigations of the electronic structure and optical properties of the GdSn1.1Ge0.9 and TbSn1.1Ge0.9 compounds. Employing the local spin density approximation accounting for strong electronic correlations in the 4f‐shell of rare‐earth ions, that is the LSDA + U method, we carry out the spin‐polarized calculations of band structure. In a broad range of wavelengths the optical constants of the compounds are measured by an ellipsometry method. A number of spectral and electronic characteristics are calculated. Based on the calculated density of states the structural features of optical conductivity for the investigated intermetallic compounds are interpreted in the region of interband absorption.

Electronic Structure of Intermetallic Antiferromagnet GdNiGe

“…To take into account the strong electron correlations of the 4f-electrons of Gd, the U correction was included for the parameters of the direct Coulomb U = 6.7 eV and Hund exchange J = 0.7 eV interactions. These values were previously calculated and used for gadolinium in [7,13].…”