Effective Hamiltonian methods for predicting the electrocaloric behavior of BaTiO 3

Abstract

The perovskite crystal BaTiO 3 is modeled using a first-principles based effective Hamiltonian and molecular dynamics simulations are performed to estimate the pyroelectric response. The electrocaloric temperature change, ΔT, is calculated for different temperatures and externally applied electric fields. It is found that it is possible to achieve a large ΔT, around 5-6 K, for a relatively small electric field gradient, less than 100 kV/cm, if the applied fields have a small absolute magnitude. © 2012 Elsevier B.V.