Effect of Sn Addition on the Structure and Optical Properties of Ge-Se-Te Chalcogenide Glasses

A series of Ge3Se5Te 2Snx(x=0, 0.4, 0.8, 1.2, 1.6, 2.0, mol%) chalcogenide glasses were prepared by tra- ditional melt-quenching method. The physiochemical properties and structure changes of glasses were characterized by employing the techniques of X-ray diffraction (XRD), differential scanning calorimetry (DSC), visible-near IR spectrum, Fourier transform infrared spectrum (FTIR), and Raman spectroscope. Physiochemical properties of Ge-Se-Te glasses change with the addition of Sn, including glass transition temperature (Tg) decreacing and infrared cut-off wavelength shifting toward long wavelength which effectively inhibits the absorption peaks of impurities in the mid-IR spectral region. In addition, the origination behind these phenomena is discussed by the average coordi- nation number calculated from Philips network-constrained theory and structural evolution of Raman spectra.