Analysis of Breit-Wigner line shapes in the Raman spectra of graphite intercalation compounds

This is the authors' abstract. We don't add key points for this paper.

We perform an analysis of the {~} 1500 cm^-1 Breit-Wigner interference feature in the Raman spectra of stage-1 (C₈X, X=K,0ex0exRb,0ex0exCs) graphite-alkali-metal intercalation compounds based on new C₈Cs data found a wider frequency range. Unlike previous studies of this interference feature we take into account the frequency dependence of the continuum scattering. Our analysis of the C₈Cs spectrum strongly suggests that the Breit-Wigner resonance at {~} 1500 cm^-1 in these C₈X donor compounds is due to an interference of a continuum with an in-plane carbon-layer vibration corresponding to the Γ-point mode of pristine graphite, rather than to the graphitic zone-folded M-point mode suggested previously.