Calculations of the p-polarized far infrared magnetoplasmon reflectivity of semimagnetic semiconductor Cd x Mn 1-x Te 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 Cd x Mn 1-x Te 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 Г, K, X and L high symmetry points of the Brillouin zone based on a microscopic secondneighbor rigid ion model (RIM).

No abstract

We have calculated the s-and p-polarized far infrared magnetoplasmon spectra of doped CdTe-Cd1−xMnxTe multi quantum wells in the presence of a static magnetic field up to 20 T parallel to the surface of the layers using a macroscopic model based on effective medium theory, using a novel approach which gives a good account of the data together with a clear physical interpretation of the various spectral features, such as the free carrier and optical phonon properties. The results show that the transverse optical modes (for the whole composition range, x = 0 to 1) are sensitive and change linearly with respect to the composition parameter. In p-polarized reflectivity the cyclotron resonance experiences a blue shift when the magnetic field strength increases. Also, the analysis of the dielectric tensor function and the Voigt dielectric function is used to determine the carriers' cyclotron effective masses (for both holes and electrons) as a function of composition. Furthermore, a modified random element iso-displacement approach has been extended for the multi layers to analyze the influence of the composition on the optical phonon response in the barrier layer.

In this work the polarized far infrared magnetoplasmon reflectivity of semimagnetic semiconductor CdxMnlixTe doped ternary alloy in the presence of magnetic field parallel to surface of sample (Voigt geometry) are used to investigate magnetoplasma and optical phonon properties. It assumed that the sample is characterized by a magnetoplasma dielectric tensor which the optical phonon contribution and free carriers (plasmon and cyclotron response) were included. The far infrared reflection spectra for S-polarization ray are independence from magnetic field, so, the ppolarized reflection spectra are interesting case to investigate. The results show the transverse optical phonon mode are sensitive to the alloy composition, x, and can be used to determine, x, value. Also, we can be used from data obtain from reflectivity of CdxMnlxTe and dependence of cyclotron and plasmon frequencies to effective mass and carrier concentration to determine the effective mass and carrier concentration of both species of carniers in the samples.