Electric field induced phase transition and electrocaloric effect in PMN-PT

TL;DR

This study uses molecular dynamics to explore electric field-induced phase transitions and the electrocaloric effect in PMN-PT, revealing maximum EC strength at the morphotropic phase boundary due to polarization rotation.

Contribution

It demonstrates the electric field-induced phase transition and maximal electrocaloric effect in PMN-PT at room temperature within the MPB region, providing insights for cooling applications.

Findings

Maximum EC strength occurs at the MPB region at 300 K.

Large temperature change is due to polarization rotation.

Electrocaloric effect is optimized near the phase boundary.

Abstract

Ferroelectric perovskite oxides possess a large electrocaloric (EC) effect, but usually at high temperatures near the ferroelectric/paraelectric phase transition temperature, which limits their potential application as next-generation solid-state cooling devices. We use classical molecular dynamics to study the electric field induced phase transitions and EC effect in PMN-PT (PbMg1/3Nb2/3O3-PbTiO3). We find that the maximum EC strength of PMN-PT occurs within the morphotropic phase boundary (MPB) region at 300 K. The large adiabatic temperature change is caused by easy rotation of polarization within the MPB region.