Light scattering from ordered and disordered stage-1 cesium graphite

Abstract

The Raman spectra of ${\mathrm{C}}_8$Cs are studied at temperatures spanning the Cs melting transition at 608 K. The spectral features and their temperature dependence are incompatible with the zone-folding model of the lattice vibrations. From an analysis of the scattered-phonon frequency dependence of the Stokes—anti-Stokes ratio and the temperature dependence of the Stokes intensity it is shown that for $\omega <600\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$ the spectral continuum characteristic of ${\mathrm{C}}_8$Cs arises from single phonon excitations and is not electronic in origin.