In isothermal processes, applying the electric field to ferroelectric materials will cause the vibrational entropy change (ΔS_vib) along with the corresponding adiabatic temperature change (ΔT_vib) induced by the intrinsic structure response, i.e., part of the electrocaloric effect (ECE). Most previous investigations only focused on the total ECE in different materials, but we found that strain engineering can regulate the ECE significantly in the typical ferroelectrics PbTiO₃ and BaTiO₃. In this paper, ΔS_vib and ΔT_vib in PbTiO₃ and BaTiO₃ are extracted using first-principles calculations and the effects of strains on the ECE are then studied. The results show that the isotropic compressive and tensile strains of up to 5% could regulate the thermodynamic properties of these materials effectively. Additionally, we find that compression can cause a positive ECE, while tension can cause a negative ECE, which is further verified by the change of Born effective charge. The calculations are accelerated (> 4×) by graphics processing units (GPUs) using the Compute Unified Device Architecture (CUDA). This method thus provides a new strategy for the regulation of ΔS_vib in the ECE.

Graphical abstract

中文翻译：

---

PbTiO 3和BaTiO 3中电热效应的应变工程

在等温过程中，对铁电材料施加电场会引起振动熵变（ΔS _vib）以及由固有结构响应（即部分电热效应（ECE））引起的相应绝热温度变化（ΔT _vib）。 ）。以前的大多数研究仅关注不同材料的总ECE，但我们发现应变工程可以在典型的铁电体PbTiO ₃和BaTiO _3中显着调节ECE 。本文中，PbTiO ₃和BaTiO _3中的ΔS _vib和ΔT _vib使用第一性原理计算提取提取物，然后研究菌株对ECE的影响。结果表明，各向同性的压缩应变和拉伸应变高达5％可以有效地调节这些材料的热力学性质。此外，我们发现压缩可导致正ECE，而张力可导致负ECE，这通过Born有效电荷的变化进一步证实。图形处理单元（GPU）使用Compute Unified Device Architecture（CUDA）将计算加速（> 4倍）。因此，该方法为ECE中的ΔS _vib的调节提供了新的策略。

图形概要