Nature of background scattering in Raman spectra of materials containing high-wavenumber vibrations

Abstract

A new interpretation for the often observed phenomenon of ‘Raman background’ is presented and discussed. It is shown that in many cases the appearance of the background for various materials (organic and inorganic) is associated with the presence of high-wavenumber ν(XH) vibrations. The nature of the observed broad band can be explained by strong anharmonic interaction between high-wavenumber excitation and low-wavenumber phonons. The results of theoretical evaluations are presented. Using the approach proposed, a good description of the unusual spectral features for several materials has been achieved. © 1997 John Wiley & Sons, Ltd.