Far-infrared spectra of Hg1-xMnxTe alloys

The infrared reflection spectra of Hg1-xMnxTe with x = 0.02, 0.04, 0.08 and 0.10 have been measured at room temperature in the spectral region from 70 to 500 cm(-1). The analysis of the far-infrared spectra was made by a fitting procedure based on the dielectric function which includes spacious distribution of free carrier influence on the plasmonphonon interaction. The influence of energy gap opening (for x approximate to 0.05) on far-infrared reflection spectra was analyzed. In spite of the strong plasmon-LO phonon interaction, we found that the long wavelength optical phonon modes of these mixed crystals showed a two-mode behavior. The model of phonon behavior based on Genzels model, was developed. This theoretical model shows very good agreement with experimental results. (C) 2002 Elsevier Science B.V. All rights reserved