Raman and infrared spectra of vitreousAs2O3

Abstract

We report the polarized reduced Raman spectra, the infrared reflectivity, and dielectric constants of bulk ${\mathrm{As}}_{2}$${\mathrm{O}}_{3}$ glass for vibrational frequencies up to 1500 ${\mathrm{cm}}^{\ensuremath{-}1}$. Longitudinal and transverse optical modes are identified in the high-frequency region, as are some features of the second-order response. The atomic motions associated with several lines are inferred from an analogy with the spectra of the tetrahedral glass Ge${\mathrm{O}}_{2}$. Our assignments bring into question the force constants previously deduced by Papatheodorou and Solin. The spectra of bulk ${\mathrm{As}}_{2}$${\mathrm{S}}_{3}$ glass and ${\mathrm{As}}_{2}$${\mathrm{Se}}_{3}$ glass are also given a parallel interpretation.