Pyroelectric properties of Pb[Zr_0.5Ti_0.5]O₃ studied with a hybrid density functional method

The primary and secondary pyroelectric coefficients of four different ordered models of lead zirconate titanate Pb[Zr_0.5Ti_0.5]O₃ solid solution have been investigated with a hybrid density functional method. Phonon anharmonicity and finite-temperature phonon properties necessary for the study of primary pyroelectricity are determined with the use of self-consistent phonon theory. Secondary pyroelectricity and lattice thermal expansion are investigated with quasi-harmonic approximation. The lattice thermal conductivity and other physical properties are also reported at the same level of theory. The largest absolute value of the pyroelectric coefficient is obtained for a rocksalt-type ordering. The results show that the pyroelectric properties of B-site solid-solution perovskites can be studied with the computational methodology previously used for simple titanate compounds BaTiO₃ and PbTiO₃, enabling further theoretical insights into computational screening of prospective new ferroelectric pyroelectrics.