Effect of annealing temperature on dielectric and pyroelectric property of highly (111)-oriented (Pb0.98La0.02)(Zr0.95Ti0.05)0.995O3 thin films

Highly (111)-oriented lanthanum modified lead zirconate titanate (Pb0.98La0.02)(Zr0.95Ti0.05)0.995O3 thin films with the thickness of 300 nm were fabricated by a sol–gel method. Electrical measurements were conducted on (Pb0.98La0.02)(Zr0.95Ti0.05)0.995O3 thin films. Well-saturated hysteresis loops were achieved with an applied voltage of 19 V. Dielectric constant and dielectric loss as a function of frequency for (Pb0.98La0.02)(Zr0.95Ti0.05)0.995O3 thin films annealed at 670 °C were measured. Dc bias field dependence of dielectric constant and dielectric loss were conducted at room temperature; the dielectric tunability of (Pb0.98La0.02)(Zr0.95Ti0.05)0.995O3 thin film annealed at 670 °C was 20.3 %. The pyroelectric coefficient of films was measured by a dynamic technique. The pyroelectric coefficients of (Pb0.98La0.02)(Zr0.95Ti0.05)0.995O3 thin films annealed at 570, 620 and 670 °C were 208, 244 and 192 μC/m2 K, respectively. It was found that the pyroelectric property was highly depended on the annealing temperature.