Inelastic light scattering from liquid and amorphous selenium

Abstract

Raman scattering measurements are reported for supercooled liquid Se at 180 C and compared with amorphous Se spectra at 25 C. The liquid spectra indicate an appreciable broadening of the high frequency optic-like band upon melting with little change in peak frequency. The phonon gap of a-Se is narrowed in l-Se with evolution toward a pseudogap with increasing temperature. Observation of a weak polarized low frequency mode near that of a-Se suggests the direct observation of rings in the liquid. The weak intensity of this mode suggests the dominant scattering by chain configurations in the Raman spectra of a-Se and l-Se.