Abstract In this work, the effective field theory is used to investigate the electrocaloric effect (ECE) of a ferroelectric nanocube with core-shell morphology described by the transverse Ising model. We have elucidated the influences of the external electric field Δ E and interfacial coupling J i n t / J c on the thermal and electrocaloric properties. The heat capacity, internal energy, entropy, and changes in entropy and adiabatic temperature as a function of temperature are discussed in detail. Moreover, the influences of the shell coupling J s / J c and the transverse field Ω / J c especially on the entropy change are examined. Our results show that the temperature dependence of the ECE depends strongly on the applied electric field, which increases its magnitude and causes a dielectric breakdown after increase of the applied electric field. However, at relatively high temperature, an enhanced ECE can be obtained. Our study implies the crucial role played by the aforementioned physical parameters to control the phase transition temperature and electrocaloric performance, which may provide further insight for a better understanding of those physical quantities.

中文翻译：

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铁电纳米立方体电热效应的理论研究

摘要 在这项工作中，有效场理论被用来研究铁电纳米立方体的电热效应（ECE），其核壳形貌由横向 Ising 模型描述。我们已经阐明了外部电场 Δ E 和界面耦合 J int / J c 对热和电热性质的影响。详细讨论了热容、内能、熵以及作为温度函数的熵和绝热温度的变化。此外，还研究了壳耦合 J s / J c 和横向场 Ω / J c 的影响，特别是对熵变的影响。我们的结果表明，ECE 的温度依赖性强烈依赖于外加电场，这会增加其幅度并在外加电场增加后导致介电击穿。然而，在相对较高的温度下，可以获得增强的 ECE。我们的研究暗示了上述物理参数在控制相变温度和电热性能方面发挥的关键作用，这可能为更好地理解这些物理量提供进一步的见解。