The electrocaloric effect (ECE) of BaZrxTi1−xO3 (BZT) is closely related to the relaxor state transition of the materials. This work presents a systematic study on the ECE and the state transition of the BZT, using a combined canonical and microcanonical Monte Carlo simulations based a lattice-based on a Ginzburg-Landau-type Hamiltonian. For comparison and verification, experimental measurements have been carried on BTO and BZT (x=0.12 and 0.2) samples, including the ECE at various temperatures, domain patterns by Piezoresponse Force Microscopy at room temperature, and the P-E loops at various temperatures. Results show that the dependency of BZT behavior of the Zr-concentration can be classified into three different stages. In the composition range of 0≤x≤0.2, ferroelectric domains are visible, but ECE peak drops with increasing Zr-concentration harshly. In the range of 0.3≤x≤0.7, relaxor features become prominent, and the decrease of ECE with Zr-concentration is moderate. In the high concentration range of x≥0.8, the material is almost nonpolar, and there is no ECE peak visible. Results suggest that BZT with certain low range of Zr-concentration around x=0.12∼0.3 can be a good candidate with relatively high ECE and simutaneously wide temperature application range at rather low temperature.
@article{arxiv.1608.05010,
title = {State transition and electrocaloric effect of BaZr$_{x}$Ti$_{1-x}$O$_3$: simulation and experiment},
author = {Yang-Bin Ma and Christian Molin and Vladimir V. Shvartsman and Sylvia Gebhardt and Doru C. Lupascu and Karsten Albe and Bai-Xiang Xu},
journal= {arXiv preprint arXiv:1608.05010},
year = {2017}
}