Observation of vibrational asymmetry in the high resolution monochromatized XPS of hydrocarbon polymers

Abstract

High resolution C1s spectra are reported for polyethylene, polypropylene, hexatriacontane ( n-C 36H 74) and polystyrene. Asymmetry is observed on the high binding energy side of the lineshape for the first three of these compounds, and is attributed to the excitation of CH stretching vibrations during core level photoionization. The effect only becomes apparent for experimental linewidths < 1.0 eV. Linewidths reported here are typically < 0.85 eV. For polystyrene a much smaller degree of asymmetry is observed.