Temperature-controlled-orientation dependence of electrical properties of Pb0.95La0.05Zr0.46Ti0.54O3 thin films

Abstract

In this work, the relationship between annealing temperature, crystallographic orientation, and electrical properties of Pb0.95La0.05Zr0.54Ti0.46O3 thin films was investigated. The films (∼210 nm) were prepared using a chemical solution deposition method and annealed in the temperature range of 550–750 °C. From the x-ray diffraction results, it was observed that high temperature annealing (650 and 750 °C) resulted in films having a mixed orientation of (110) and (001) with no pyrochlore phase, whereas low temperature annealing (550 °C) resulted in films with mixed phases. The ferroelectric properties of the films were studied using a metal/ferroelectric/metal model. The capacitance–voltage curves were used to calculate the free carrier concentration (FCC) and built-in potential. The annealing temperature was observed to control the orientation, which in turn affects the electrical properties. Films annealed at higher temperature exhibit higher capacitance, remanent polarization, and FCC but lower coercive voltage, loss tangent, and built-in potential as compared to the film annealed at 550 °C. Thus, high temperature annealing enhances (110) orientation and suppresses the pyrochlore phase in the films which helps in improving the electrical properties.