RAMAN AND INFRARED-SPECTRA OF VITREOUS AS2O3

We report the polarized reduced Raman spectra, the infrared reflectivity, and dielectric constants of bulk As2O3 glass for vibrational frequencies up to 1500 cm-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 GeO2. Our assignments bring into question the force constants previously deduced by Papatheodorou and Solin. The spectra of bulk As2S3 glass and As2Se3 glass are also given a parallel interpretation. © 1979 The American Physical Society.