Optical properties of Hg1−xMnxTe1−ySey

Far-infrared reflectivity spectra of Hg1−xMnxTe1−ySey (0.01 ⩽ x ⩽ 0.14, 0.01 ⩽ y ⩽ 0.1) single crystals were measured in the 80-420 cm−1 range at room temperature. The analysis of the far-infrared spectra was made by a fitting procedure based on the model of coupled oscillators. The dependence of plasma frequency and phonon modes on composition was determined. A model for phonon behavior in quaternary mixed crystals of the type A1−xBxC1−yDy was developed, too. This model was tested for Hg1−xMnxTe1−ySey.