Polarized far infrared magnetoplasmon refiectivity of doped CdxMn1-xTe semimagnetic semiconductor in the Voigt configuration

摘要

Calculations of the p-polarized far infrared magnetoplasmon reflectivity of semimagnetic semiconductor CdxMn1-xTe doped ternary alloy in the presence of a magnetic field parallel to the surface of the sample (the Voigt geometry) are used to investigate magnetoplasmon and zone center optical phonon frequencies. It is assumed that the sample is characterized by a dielectric tensor in which the optical phonon contribution and free carriers (plasmon and cyclotron response) are included. The results show that the transverse optical phonon mode is sensitive to the alloy composition, x, and can be used to determine the value of x. The longitudinal optical phonon frequencies are shifted due to phonon-plasmon coupling in doped samples. Also, the influence of composition on the vibrational modes in zinc blende CdxMn1-xTe is described within a modified random element isodisplacement (MREI) approach. By indicating the plasmon and cyclotron frequencies from p-polarized reflectivity spectra and the Voigt permittivity, we calculated the carrier concentration and the effective masses of the carriers. Furthermore, we indicate the frequencies of the phonons at the Gamma, K, X and L high symmetry points of the Brillouin zone based on a microscopic second-neighbor rigid ion model (RIM). (C) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.