中文摘要：

从Landau-Devonshire唯象理论出发,通过热力学分析得到了PbZr0.4Ti0.6O3体材料和薄膜的电热效应与温度和电场的关系。结果表明,在居里温度附近,体材料发生铁电相变,而在足够强的电场下,其固有的电热效应破坏了铁电相变的不连续性,绝热温度改变了约11K,对薄膜结构的PbZr0.4Ti0.6O3,绝热温度改变了约7.3K,这与实验结果（12K）基本相符。薄膜结构使铁电材料由不连续相变转到连续相变,它还减小了铁电材料的电热效应,降低了各物理量随温度变化的灵敏性。

英文摘要：

The electrocaloric effect dependence of temperature and electric field in bulk and laterally clamped （thin film） PbZr0.4 Ti0.6 O3 was investigated using a thermodynamic analysis via the Landau-Devonshire＇s phenomenological theory. The results show that near the Curie temperature, phase transition discontinuously transform from cubic to tetragonal for bulk PbZr0.4 Ti0.6 O3. At a sufficiently large electric field, The intrinsic electrocaloric coefficient destroys the discontinuity and results in an adiabatic temperature change of 11 and 7. 3K for cubic and thin film respectively, which agrees closely with the value of 12K observed experimentally for PbZr0.95 Ti0.05O3 thin film. Perfect thin film transforms the discontinuous transition into a continuous transition, which decreases the electrocaloric effect and reduce its dependence on temperature.