Elastocaloric response of PbTiO3 predicted from a first-principles effective Hamiltonian

TL;DR

This study uses a first-principles effective Hamiltonian and molecular dynamics to investigate the elastocaloric effect in PbTiO3, revealing how stress influences transition temperature and domain formation impacts efficiency.

Contribution

It introduces a first-principles based effective Hamiltonian approach to predict elastocaloric behavior in PbTiO3 under uniaxial stress.

Findings

Transition temperature varies linearly with uniaxial tensile stress

Negative temperature change occurs when stress is removed

Domain structures reduce elastocaloric effectiveness

Abstract

A first-principles based effective Hamiltonian is used within a molecular dynamics simulation to study the elastocaloric effect in PbTiO3. It is found that the transition temperature is a linear function of uniaxial tensile stress. Negative temperature change is calculated, when the uniaxial tensile stress is switched off, as a function of initial temperature Delta-T(T_initial). It is predicted that the formation of domain structures under uniaxial tensile stress degrades the effectiveness of the elastocaloric effect.