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The electronic structure and optical properties of nonstoichiometric ErNi2Mnx compounds (with х = 0, 0.5, 1) have been studied. Spin-polarization calculations of the total and partial densities of electron states have been performed in terms of DFT + U method with a correction for strong electronic correlations in the 4f shell of Er in the approximation of ErNi2 –xMnx solid-solution. The peculiarities of transformations of the densities of electron states Have been determined depending on the manganese content. The optical properties of these compounds have been studied over a wide wave length range. The calculated interband optical conductivity spectra have been compared with the dependences obtained experimentally. The origin of the quantum absorption of light is discussed. The plasma and relaxation frequencies of current carriers have been determined. [ABSTRACT FROM AUTHOR]

This paper presents electronic spectrum calculations and a study of the optical properties of the binary compounds Mn70Al30 and Mn80Al20 with the β-Mn structure. The energy dependences of the calculated density of states, with high values at the Fermi level, are determined by broad bands formed by manganese 3d states. The calculated electronic structures are used to analyze measured optical conductivity spectra of the alloys in the quantum light absorption range. From their optical properties in the infrared spectral region, we evaluate a number of characteristics of conduction electrons. [ABSTRACT FROM AUTHOR]

Results of calculations of the electronic structure and studies of the optical properties of the Mn3Al compound in the two-phase crystalline state are reported. The calculated densities of electron states are determined by the wide (~8 eV) 3d band of Mn atoms; the Fermi level is localized within the range of high densities of states. The nature of quantum light absorption is discussed based on the comparison of experimental and theoretical spectra of the interband optical conductivity. It is shown that the calculated structure of energy bands of the compound allows us to qualitatively interpret the frequency dispersion of this spectral parameter. [ABSTRACT FROM AUTHOR]

The structure and optical properties of the Mn2FeAl Heusler alloy have been investigated. It is shown that the alloy crystallizes into a structure of the β-Mn type. The behavior of the optical conductivity of the alloy, which is anomalous for metallic systems (namely, the absence of a contribution from the intraband absorption and the presence of the intensive interband absorption), is observed in the IR spectral range. It is shown that this behavior is due to the following peculiarities of the electronic structure: the Fermi level is located in the region of a high density of states formed by the d states of Mn and Fe atoms. [ABSTRACT FROM AUTHOR]

The optical constants of the color intermetallic compounds PdGd and Pd3Gd are measured by the polarimetric method. Frequency dispersions of the complex permittivity, optical conductivity, and reflectivity, and also the microcharacteristics of the conduction electrons — plasma and relaxation frequencies — are calculated. The energy dependences of these parameters are compared with similar characteristics obtained for this type of compound of palladium with scandium, terbium, and lutecium. [ABSTRACT FROM AUTHOR]

Abstract: The experimental study of the optical properties of CeNi5, CeNi4Cu and CeNi4Al compounds was carried out in the 0.083–5.64eV energy range using the ellipsometry method. The optical constants, dielectric functions and electronic parameters (plasma and relaxation frequencies) were determined. The energy dependencies of the optical interband conductivities are discussed by using the available information on the electronic band structure of these compounds. In the ternary alloys the optical spectra show the presence of peculiarities related to effect of Cu or Al substitution at Ni sites. [ABSTRACT FROM AUTHOR]