V. V. Nemoshkalenko

Magneto-optical spectroscopy of d- and f-ferromagnetic materials: recent theoretical progress (Review Article)

The current status of theoretical understanding of the optical and magneto-optical (MO) spectra of 3d, 4f and 5f compounds is reviewed. Energy band theory based upon the local spin-density approximation (LSDA) describes the optical and MO spectra of transition metal compounds reasonably well. Examples which we examine in detail are XPt3 compounds (with X=3d V, Cr, Mn, Fe, and Co) in the AuCu3 structure, ternary Heusler alloys NiMnSb, PdMnSb, PtMnSb, and MnBi compound. The LSDA, which is capable of describing the spectra of transition-metal alloys with high accuracy, does not suffice for lanthanide compounds having a correlated 4f shell. A satisfactory description of the optical spectra could be obtained by using a generalization of the LSDA, in which explicitly f electron Coulomb correlations are taken into account (LSDA+U approach). As examples of this group we consider CeSb and CeBi. For CeSb a record Kerr angle of 90° was very recently reported, 90° is the absolute maximum value that can be measured. I...

Theoretical and experimental investigation of X-ray O- and N-emission spectra of tungsten

Abstract The experimental investigation of the OIIINVI, VII-emission spectrum of pure tungsten and tungsten in W2C is carried out. The experimental data are compared with the theoretical calculation of the intensity in the OIIINVI, VII-emission spectrum of tungsten. A good agreement is obtained between the theoretical and experimental spectra. The conclusion was drawn, that the earlier published experimental data on the OIIINVI,VII- spectrum of tungsten referred to carbide of tungsten.

Experimental and theoretical study of the optical properties of crystalline and amorphous TiSi2 films

Optical properties of amorphous and polycrystalline TiSi2 films have been studied experimentally in a wide spectral range (0.5–5.0u2009eV). The structures in the optical conductivity spectrum of polycrystalline TiSi2 sample are explained on the basis of comparison of the experimental data and the calculated data. Theoretical spectra were obtained within the local-density approximation using the semirelativistic linear-muffin-tin-orbital method (LMTO). It is shown that the transition of crystalline TiSi2 to the amorphous state leads to significant changes in the optical properties.

THE FERMI SURFACES OF La2−xSrxCuO4 AND YBa2Cu3O7

The theoretical investigation of the Fermi surface (FS) and constant-energy one near the Fermi energy of La2−xSrxCuO4 and YBa2Cu3O7 is the aim of this work.