Theoretical Calculations of Refractive Properties for Hg(3)Te(2)Cl(2) Crystals

This paper reviews the optical properties, such as refractive index, optical dielectric constant, and reflection coefficient of the Hg(3)Te(2)Cl(2) crystals. The applications of the Hg(3)X(2)Y(2) crystals as electronic, optical, and optoelectronic devices are very much determined by the nature and magnitude of these fundamental material properties. The origin of chemical bonding in the crystals is very important for definition of the physical and chemical properties. The main structural feature of the Hg(3)X(2)Y(2) crystals is the presence of covalent pyramids [XHg(3)] and linear X-Hg-X groups. Optical properties are calculated according to the model proposed by Harrison. The refractive index in the spectral region far from the absorption edge is determined within the generalized single-oscillator model. The calculated results are found to be in good agreement with experimental data.