Effect of Electronic Correlations on the Electronic Structure, Magnetic and Optical Properties of the Ternary RCuGe Compounds with R = Tb, Dy, Ho, Er

Abstract

In this study, the ab initio and experimental results for RCuGe ternary intermetallics were reported for R = Tb, Dy, Ho, Er. Our theoretical calculations of the electronic structure, employing local spin density approximation accounting for electron–electron correlations in the 4f shell of Tb, Dy, Ho, Er ions were carried in DFT+U method. The optical properties of the RCuGe ternary compounds were studied at a broad range of wavelengths. The spectral and electronic characteristics were obtained. The theoretical electron densities of states were taken to interpret the experimental energy dependencies of the experimental optical conductivity in the interband light–absorption region. From the band calculations, the 4f shell of the rare-earth ions was shown to provide the major contribution to the electronic structure, magnetic and optical properties of the RCuGe intermetallics. The accounting for electron–electron correlations in Tb, Dy, Ho, Er resulted in a good agreement between the calculated and experimental magnetic and optical characteristics.

Magnetic phenomena in equiatomic ternary rare earth compounds

“…Crystal structures of RCuGe compounds show similarity with RCuSi as the crystal structure depends on the annealing treatment of the materials. As cast samples of RCuGe (R= La-Lu) crystallize in the AlB2 type hexagonal crystal structure and after long time annealing the compounds with R= Tb -Lu adopt CaIn2 type hexagonal crystal structures [150][151][152][153][154][155]. CaIn2 and LiGaGe and CeCu2 type hexagonal crystal structures were identified in RCuSn series of compounds.…”