Papers by Author: V.I. Kovalev

Abstract: Optical and magneto-optical properties of GaMnSb layers fabricated on GaAs (001) substrates by laser ablation technique were studied using spectral ellipsometry (E =1.24-3.25 eV) and the transversal Kerr effect (TKE) (E = 0.5 4.2 eV) as well as atomic and magnetic force microscopy. Spectra of the constituents of the diagonal components of the permittivity tensor as well as TKE depended substantially on the layer fabrication conditions. At room temperature a strong resonant band was observed in the TKE spectra for the GaMnSb layers with low Mn content in the energy range E 0.5-1.5 eV. This resonant TKE band was explained by excitation of surface plasmons in MnSb nanoclusters, which arose during the growth of the layers. In the energy region E >1.5 eV the TKE spectra were related to interband transitions in MnSb inclusions.

Abstract: Optical and magneto-optical properties of In(Ga)MnAs layers fabricated by laser ablation on GaAs(100) substrates were studied. Spectra of the optical constants and the transversal Kerr effect (TKE) depended substantially on the conditions of layer fabrication and testified to the presence of MnAs inclusions in all the samples. The cross-sectional transmission electron microscopy revealed the presence in the layers of inclusions 10-40 nm in size. At room temperature, a strong resonant band was observed in the TKE spectra of some In(Ga)MnAs layers in the energy range 0.5-2.7 eV. The resonant character of the TKE spectra was explained by excitation of surface plasmons in the MnAs nanoclusters embedded in the semiconductor host.