Search

Your search keyword '"Kuz'min, Yu. I."' showing total 232 results
Start Over Author "Kuz'min, Yu. I."
232 results on '"Kuz'min, Yu. I."'

10. Electronic structure and optical properties of superconducting compounds ScGa3 and LuGa3.

Author

Knyazev, Yu. V., Lukoyanov, A. V., and Kuz'min, Yu. I.

Subjects
OPTICAL properties, OPTICAL conductivity, ELECTRONIC density of states, OPACITY (Optics), LIGHT absorption, PHOTONS, ELECTRONIC structure, CONDUCTION electrons
Abstract

The optical properties of bulk AuCu3-type ordered superconducting binary compounds ScGa3 and LuGa3 have been experimentally investigated for the first time in the wide spectral range and explained in terms of the band structure. First-principles calculations of electronic densities of states and optical conductivities are performed within the framework of LSDA+U method using the LMTO-ASA software package. The measured dielectric functions spectra for both materials exhibit a strong absorption region above ∼ 1 eV, which are in a reasonable agreement with the calculated metal-like energy structures of compounds. Features of quantum light absorption are discussed on the basis of a comparative analysis of experimental and theoretical spectra of interband optical conductivity. Plasma and relaxation frequencies of conduction electrons are determined. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

12. Experimental and theoretical investigations on magnetic and related properties of ErRuSi

Author

Gupta, Sachin, Das, A., Suresh, K. G., Hoser, A., Knyazev, Yu. V., Kuz'min, Yu. I., and Lukoyanov, A. V.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

We report experimental and theoretical studies of magnetic and related properties of ErRuSi compound. Various experimental techniques such as neutron diffraction, magnetization, magneto-thermal, magneto-transport, optical have been used to study the compound. Neutron diffraction shows ferromagnetic ordering at low temperatures with moments aligned in ab plane. Neutron diffraction and magnetization data show reduction in magnetic moment, which may be due to crystalline electric field effects at low temperatures. The compound shows good magnetocaloric properties with a low field adiabatic temperature change of 4.7 K, which is larger than that of many proposed materials for magnetic refrigeration at low temperatures. Magnetoresistance shows large negative value at 8 K, which changes its sign and increases in magnitude, with decrease in temperature and/or increase in field. The positive MR at low temperatures attributed to the Lorentz force effect. The electronic structure calculations accounting for electronic correlations of the 4f electrons of Er reproduces the ferromagnetic ordering and effective magnetic moment. Interband transitions between the Ru and Er d states and Er f states in one spin projection are found to form the main features of the measured optical conductivity in this compound., Comment: 14 pages, 10 figures

Published
2014
Full Text
View/download PDF

18. Electronic structure, magnetic and optical properties of intermetallic compounds R2Fe17 (R=Pr,Gd)

Author

Knyazev, Yu. V., Lukoyanov, A. V., Kuz'min, Yu. I., Kuchin, A. G., and Nekrasov, I. A.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

In this paper we report comprehensive experimental and theoretical investigation of magnetic and electronic properties of the intermetallic compounds Pr2Fe17 and Gd2Fe17. For the first time electronic structure of these two systems was probed by optical measurements in the spectral range of 0.22-15 micrometers. On top of that charge carriers parameters (plasma frequency and relaxation frequency) and optical conductivity s(w) were determined. Self-consistent spin-resolved bandstructure calculations within the conventional LSDA+U method were performed. Theoretical interpetation of the experimental s(w) dispersions indicates transitions between 3d and 4p states of Fe ions to be the biggest ones. Qualitatively the line shape of the theoretical optical conductivity coincides well with our experimental data. Calculated by LSDA+U method magnetic moments per formula unit are found to be in good agreement with observed experimental values of saturation magnetization., Comment: 16 pages, 5 figures, 1 table

Published
2006
Full Text
View/download PDF

38. The Electronic Structure and Optical Spectroscopy of ErNi2Mnx Compounds.

Author

Knyazev, Yu. V., Lukoyanov, A. V., Kuz'min, Yu. I., Gerasimov, E. G., and Mushnikov, N. V.

Subjects
ELECTRON density, LIGHT absorption, OPTICAL spectra, OPTICAL properties, PLASMA frequencies, OPTICAL spectroscopy, ELECTRONIC structure
Abstract

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]

Published
2023
Full Text
View/download PDF

48. Energy Spectrum and Optical Absorption of Mn100 –хAlх (x = 20, 30) Compounds with the β-Mn Structure.

Author

Knyazev, Yu. V., Lukoyanov, A. V., Kuz'min, Yu. I., Dash, Shubhra, Patra, Ajit K., and Vasundhara, M.

Subjects
OPTICAL spectra, LIGHT absorption, ABSORPTION spectra, OPTICAL properties, OPTICAL conductivity
Abstract

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]

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results