Giant caloric effects enhanced by the helix polarization at the 180° domain wall in tetragonal BaTiO3

H Zhang; P F Tan; B Li; F Wang; J B Wang; X L Zhong; W Wang

doi:10.1088/1361-648X/ab3d6e

Giant caloric effects enhanced by the helix polarization at the 180° domain wall in tetragonal BaTiO₃

J Phys Condens Matter. 2019 Dec 11;31(49):495702. doi: 10.1088/1361-648X/ab3d6e. Epub 2019 Aug 21.

Authors

H Zhang¹, P F Tan, B Li, F Wang, J B Wang, X L Zhong, W Wang

Affiliation

¹ Hunan Provincial Key Laboratory of Health Maintenance for Mechanical Equipment, Hunan University of Science and Technology, Hunan, Xiangtan 411201, People's Republic of China. School of Materials and Engineer1ing, Xiangtan University, Hunan, Xiangtan 411105, People's Republic of China.

PMID: 31434066
DOI: 10.1088/1361-648X/ab3d6e

Abstract

The electrocaloric and elastocaloric properties at the 180° domain wall in the tetragonal BaTiO₃ are studied using the Landau-Ginzburg-Devonshire model as a function of the domain wall rotation angle α. The Ising-Bloch character is predicted at the 180° domain wall in tetragonal BaTiO₃ under the flexoelectric effect. The electric field-induced adiabatic temperature change (ΔT _E) which is induced by the Bloch-type polarization component depends on α, and a giant positive ΔT _E appears at α = (π + 12n)/24 where n is an integer. The asymmetry of ΔT _E is found around the Bloch-type domain wall. The Bloch-type polarization component has a little contribution to the stress-induced adiabatic temperature change. This calculation indicates a contribution of helix polarization at the domain wall on the caloric effects (CEs) in the ferroelectric materials.