Ferroelectric SrBi₂Ta₂O₉Thin Film Studied by Micro-Raman Scattering and Atomic Force Microscopy

Abstract

O 9 thin films were prepared by metal-organic decomposition technique on Si wafers. The thickness dependence of the films was studied by microRaman scattering and atomic force microscopy (AFM). From the AFM observation, it is found that films were constructed of c-axis-oriented grains. The low frequency component of the Raman spectra of the films decreases as the temperature increases. The spectral analysis of the low frequency component has been carried out by using a damped harmonic-oscillator model and a relaxational model. The relaxation time has the similar value of that reported in KDP. It is suggested the physical origin of the low frequency component may be polarization fluctuation.