Temperature dependence of ferroelectric and dielectric properties of PbZr_0.5Ti_0.5O₃ thin film based capacitors

The temperature dependence of the ferroelectric and dielectric properties of PbZr_0.5Ti_0.5O₃ thin films deposited on LaNiO₃-coated SrTiO₃ substrate was investigated. The results showed that both the saturation polarization and remanent polarization increased with decreasing temperature from 300 to ∼50 K, and decreased as the temperature continued to decrease below 40 K. The capacitance of the PbZr_0.5Ti_0.5O₃ ferroelectric thin film capacitor as a function of small ac field and temperature was measured, and the data were processed using Rayleigh law. It was demonstrated that both the reversible and irreversible contributions to the dielectric constant decreased with decreasing temperature; however, they showed an increase when the temperature dropped below 50 K. The anomalous behavior of the temperature dependence may be attributed to a phase transition in the PbZr_0.5Ti_0.5O₃ thin film in the vicinity of 50 K. © 2002 American Institute of Physics.