Ferroelectric relaxation of (Pb0.76Ca0.24)TiO3 thin film

Ferroelectric relaxation of sol–gel prepared tetragonal (Pb0.76Ca0.24)TiO3 (PCT) thin film was investigated with piezoelectric response atomic force microscopy (AFM). The result was compared with the dielectric relaxation measured by LCR meter. It is found that the dielectric relaxation is much slower than ferroelectric relaxation. On the basis of a comprehensive survey of retention loss models and detailed analysis of experimental data it is proposed that the dielectric relaxation is due to domain wall depression and the ferroelectric relaxation was due to the depolarisation effect. An activation field of 668 kV/cm was obtained from model fitting and it is higher than existing data for PZT. This higher activation field contributes to the good retention property of the film.