Effect of isomorphic atom substitution on the refractive index and oscillator parameters of TlInS2xSe2(1-x) (0.25 <= x <= 1) layered mixed crystals

The optical properties of TlInS2xSe2(1-x) mixed crystals (0.25 <= x <= 1) have been studied at room temperature through the transmittance and reflectivity measurements in the wavelength range of 400-1100 nm. The spectral dependence of the refractive index for all compositions of studied crystals were obtained. The dispersion of the refractive index is discussed in terms of the Wemple-DiDomenico single-effective-oscillator model. The compositional dependencies of refractive index dispersion parameters: oscillator energy, dispersion energy and zero-frequency refractive index were revealed. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim