Far-infrared study of amorphous Ge0.17Se0.83-xSbx chalcogenide glasses

Far-infrared transmission spectra of Ge0.17Se0.83-xSbx (x = 0, 0.03, 0.09, 0.12, 0.15) glassy alloys are obtained in the spectral range 500-200 cm(-1) at room temperature. The results are interpreted in terms of the vibrations of the isolated molecular units, in such a way as to preserve fourfold and twofold coordination for Ge and Se atoms, respectively. In the Ge0.17Se0.83 bulk glass the main absorption bands appear at similar to 250 cm(-1) and 300 cm(-1). With the increase in Sb content some new bands start appearing at 228-231 cm(-1) and 250-260 cm(-1). Theoretical calculations (bond energy, relative probability density of bond formation, force constant and wave number) were also made to justify the results. (C) 2009 Elsevier B.V. All rights reserved.