Enhancing the electrocaloric effect in a relaxor polymer by including minor normal ferroelectric phase
Enhancing the electrocaloric effect in a relaxor polymer by including minor normal ferroelectric phase
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DOI：
10.1063/1.5054114
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发表时间：
2018-10
影响因子：
4
通讯作者：
Biao Lu;Xin Chen;Tian Zhang;Shengguo Lu;Qiming Zhang
中科院分区：
文献类型：
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作者：
Biao Lu;Xin Chen;Tian Zhang;Shengguo Lu;Qiming Zhang
在低磁场下产生大的热效应是实现高性能固态热制冷的关键。在这里，我们报告说，一个大的增强电热响应在一个温和的电场水平在一个相对较宽的温度范围内可以实现在松弛聚（偏氟乙烯-三氟乙烯-氯氟乙烯）[P（VDF-TrFE-CFE）]聚合物，包括次要的正常铁电相。结果表明，P（VDF-TrFE-CFE）69.7/30.3/6 mol.在90 MV/m的中等电场下，含有少量正常铁电相的三元共聚物的绝热温变ΔT = 11 K，而含有纯弛豫相的三元共聚物的绝热温变ΔT = 6 K。结果表明，次要铁电相的存在有利于在铁电转变附近的温度范围内的极化开关，而弛豫相保持在一个较宽的温度范围内的大的电热效应（ECE），导致在一个相对较宽的温度范围内的材料中的大的ECE。
Generating a large caloric effect under a low applied field is critical for realizing high performance solid state caloric cooling. Here, we report that a large enhancement in the electrocaloric response at a moderate electric field level over a relatively broad temperature range can be achieved in the relaxor poly(vinylidenefluoride-trifluoroethylene-chlorofluoroethylene) [P(VDF-TrFE-CFE)] polymers by including the minor normal ferroelectric phase. We show that the terpolymer of P(VDF-TrFE-CFE) 69.7/30.3/6 mol. % which contains a minor normal ferroelectric phase, under a moderate electric field of 90 MV/m, can reach an adiabatic temperature change ΔT = 11 K, compared with ΔT = 6 K of the terpolymers with a pure relaxor phase under the same field. The results reveal that the presence of the minor ferroelectric phase facilitates the polarization switch in a temperature range near the ferroelectric transition while the relaxor phase maintains a large electrocaloric effect (ECE) over a broad temperature range, resulting in a large ECE over a relatively broad temperature range in the material.