LIGHT-SCATTERING FROM ORDERED AND DISORDERED STAGE-1 CESIUM GRAPHITE

The Raman spectra of C8Cs 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 ω<600 cm-1 the spectral continuum characteristic of C8Cs arises from single phonon excitations and is not electronic in origin. © 1979 The American Physical Society.