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

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Materials Science

Background:

• Lead zirconate titanate (Pb[Zr0.5Ti0.5]O3) is a key material in ferroelectric and piezoelectric applications.
• Understanding pyroelectric properties is crucial for developing advanced dielectric materials.
• Computational methods offer a powerful approach to predict and optimize material properties.

Purpose of the Study:

• To investigate the primary and secondary pyroelectric coefficients of ordered Pb[Zr0.5Ti0.5]O3 models.
• To explore the influence of phonon anharmonicity and thermal expansion on pyroelectricity.
• To establish a computational framework for screening new ferroelectric pyroelectric materials.

Main Methods:

• Hybrid density functional theory (DFT) was employed.
• Self-consistent phonon theory was used to determine phonon anharmonicity and finite-temperature phonon properties.
• Quasi-harmonic approximation (QHA) was applied to study secondary pyroelectricity and lattice thermal expansion.

Main Results:

• The largest absolute pyroelectric coefficient was observed for a rocksalt-type ordering model.
• Phonon anharmonicity and thermal expansion effects on pyroelectricity were quantified.
• Lattice thermal conductivity and other physical properties were calculated.

Conclusions:

• The computational methodology is effective for studying pyroelectric properties in B-site solid-solution perovskites.
• This approach enables theoretical insights for the computational screening of novel ferroelectric pyroelectrics.
• The findings guide the design of materials with enhanced pyroelectric responses.