Optical Phonons in Amorphous Silicon Oxides. II. Calculation of Phonon Spectra and Interpretation of the IR Transmission of SiOx

Basing on the theoretical investigations of Part I of this work a simple model for the calculation of the density of vibrational modes and of the IR response function of the geometrically and chemically disordered material SiOx (0 < x ≦ 2) is developed. This model leads for the first time to a theoretical interpretation of LO—TO splittings and of chemical shifts of the minima of IR transmission spectra of thin SiOx films prepared by reactive sputtering.