Enhancing the electrocaloric effect of PbZr0.4Ti0.6O3/PbTiO3 superlattices via composition tuning
Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education, Xiangtan University - Hunan Xiangtan 411105, China
2 Faculty of Materials, Optoelectronics and Physics, Xiangtan University - Hunan Xiangtan 411105, China
3 Department of Materials Science and Engineering, National University of Singapore - Singapore 117574
Accepted: 1 August 2011
A thermodynamic model is developed to investigate the electrocaloric effect (ECE) of the PbZr0.4Ti0.6O3/PbTiO3 ferroelectric superlattices. The ECE of a superlattice consisting of ferroelectric layers A and B with thickness hA and hB is calculated as a function of the thickness fraction βA=hA/(hA+hB). An ECE anomaly could be found at the specific composition. In particular, we found that a maximum adiabatic temperature change (ΔT=5.3 K) appears for the critical thickness of PbTiO3. This large ECE is attributed to the large change in spontaneous polarization associated with the phase transform, caused by the misfit strain between the ferroelectric sublayers.
PACS: 77.70.+a – Pyroelectric and electrocaloric effects / 77.80.B- – Phase transitions and Curie point / 75.70.Cn – Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
© EPLA, 2011