IR spectroscopy of PbTiO3 thin films obtained from different annealing methods

Polycrystalline PbTiO3 thin films have been prepared by rapid thermal annea ling (RTA) and slow rate annealing (SRA) methods based on a modified sol-ge l process. Infrared (IR) reflectance spectra have been carried out to study the PbTiO3 thin films. All eight IR active phonon modes have been observed in the films. Differences in frequencies of the corresponding phonon modes in sample prepared from RTA and SRA methods are also obtained: the frequen cies of most phonon modes in the former case are lower than that in the lat ter. Stress in the thin films is considered to be the dominant factor to af fect the actions of phonon modes, especially the soft modes.