Dielectric properties of relaxor ferroelectric films

Dielectric properties of the relaxor films are theoretically investigated with the Monte Carlo simulation. We find that the size effect on the dielectric susceptibility of films is neglectable while the influence of the surface layer of the film is overlooked. On the contrary, while the surface layer is explicitly considered, we observe a systematic increase of T-m (the temperature at which the dielectric susceptibility reaches the maximum) and a systematic decrease of the maximum dielectric susceptibility as the film thickness decreases. An additional broadening of the transition region around T-m and the frequency dispersion of the dielectric susceptibility above T-m are also observed. The mechanism responsible for these phenomena is presented.