title: Large Electrocaloric Effect in Relaxor Ferroelectric and Antiferroelectric Lanthanum Doped Lead Zirconate Titanate Ceramics.
abstract: Both relaxor ferroelectric and antiferroelectric materials can individually demonstrate large electrocaloric effects (ECE). However, in order to further enhance the ECE it is crucial to find a material system, which can exhibit simultaneously both relaxor ferroelectric and antiferroelectric properties, or easily convert from one into another in terms of the compositional tailoring. Here we report on a system, in which the structure can readily change from antiferroelectric into relaxor ferroelectric and vice versa. To this end relaxor ferroelectric Pb0.89La0.11(Zr0.7Ti0.3)0.9725O3and antiferroelectric Pb0.93La0.07(Zr0.82Ti0.18)0.9825O3ceramics were designed near the antiferroelectric-ferroelectric phase boundary line in the La2O3-PbZrO3-PbTiO3phase diagram. Conventional solid state reaction processing was used to prepare the two compositions. The ECE properties were deduced from Maxwell relations and Landau-Ginzburg-Devonshire (LGD) phenomenological theory, respectively, and also directly controlled by a computer and measured by thermometry. Large electrocaloric efficiencies were obtained and comparable with the results calculated via the phenomenological theory. Results show great potential in achieving large cooling power as refrigerants.
authors.affiliation: Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou, 510006, China.
authors.forename: Biao
authors.initials: B
authors.lastname: Lu
authors.affiliation: Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou, 510006, China.
authors.forename: Peilian
authors.initials: P
authors.lastname: Li
authors.affiliation: Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou, 510006, China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Tang
authors.affiliation: Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou, 510006, China.
authors.forename: Yingbang
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou, 510006, China.
authors.forename: Xingsen
authors.initials: X
authors.lastname: Gao
authors.affiliation: Angewandte Physik, Universität Duisburg-Essen, D-47048, Duisburg, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kleemann
authors.affiliation: Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology, Guangzhou, 510006, China.
authors.forename: Sheng-Guo
authors.initials: SG
authors.lastname: Lu