Electrocaloric effect in BaTiO3 thin films

The modified transverse Ising model taking into account the four-spin exchange quantum fluctuation, as well its the mechanical constraint of the Substrate. IS Constructed and applied to investigate the electrocaloric effect (ECE) in BaTiO3 thin films It iS found that the temperature dependence of ECE strongly depends on both the four-spm exchange interaction and quantum fluctuation. Most importantly, we achieve the adiabatic temperature change Delta T = 11.78 K at T-m = 490 K. which call be comparable with that observed experimentally in PbZr095Ti005O3 thin films and ferroelectric polymers. Furthermore. the internal stresses resulting from the clamping effect of the Substrate play I crucial role in the ECE of ferroelectric films. Control of the misfit stress by appropriate choice Of substrate provides an effective means to Improve (lie adiabatic temperature change for use in cooling or thermodielectric power conversion devices (C) 2009 American Institute of Physics [doi: 10.1063/1.3253736]