Pyroelectric vector and related polarization effects

TL;DR

This paper investigates the pyroelectric vector in polar crystals, providing a formula for its bulk value based on charge distribution symmetry, with applications to specific ferroelectric materials.

Contribution

It derives a general formula for the pyroelectric vector as a bulk property linked to charge distribution symmetry, clarifying its invisibility in equilibrium.

Findings

Verified the invisibility of the pyroelectric vector in equilibrium.

Derived a bulk formula for the pyroelectric vector based on inversion symmetry.

Discussed applications to ferroelectric perovskites BaTiO3, PbTiO3, and KNbO3.

Abstract

The principal fact that the pyroelectric vector $\Pb^0$ typical of polar crystals is invisible in equilibrium has been verified. Nevertheless, the general formula for $\Pb^0$ as a definite bulk quantity associated only with the inversion properties of a given charge distribution in the bulk has been obtained. Its application to ferroelectric perovskites BaTiO$_3$, PbTiO$_3$, and KNbO$_3$ is discussed.