Traditional ferroelectric materials, such as lead zirconate titanate (PZT) ceramics, exhibit positive strain when subjected to an electric field along the polarization direction. In contrast, the piezoelectric polymer polyvinylidene fluoride (PVDF) and its copolymer P(VDF-TrFE) display unique negative strain properties. While extensive research has focused on understanding the origin and mechanisms of this negative strain, limited efforts have been directed toward regulating these properties. This study optimizes the electro-strain and ferroelectric properties of P(VDF-TrFE) piezoelectric films through the synergistic effect of PbTiO₃ nanosheets and an in-situ electrostatic field. Our results demonstrate that while the incorporation of PbTiO₃ nanosheets does not notably enhance ferroelectricity, it significantly improves electro-strain properties, particularly negative strain, which increases from –0.097% to –0.185%, an enhancement of 91%. Moreover, the ferroelectric polarization and positive strain of P(VDF-TrFE) are further enhanced under the combined influence of PbTiO₃ nanosheets and in-situ electrostatic field, increasing maximum polarization from 10.79 μC/cm² to 13.16 μC/cm², a 22% improvement, and positive strain from 0.213% to 0.267%, a 25% enhancement. We propose a possible mechanism for these improvements, attributed to the enhanced flexibility of the amorphous phase and increased content of polar β-phase in P(VDF-TrFE) films under this synergistic effect. This work highlights novel strategies for controlling the electro-strain and ferroelectric properties of P(VDF-TrFE) piezoelectric films.

中文翻译：

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PTO纳米片与原位静电场协同作用下P（VDF-TrFE）薄膜的电应变和铁电性能优化


传统的铁电材料，如锆钛酸铅 （PZT） 陶瓷，在沿极化方向受到电场时表现出正应变。相比之下，压电聚合物聚偏二氟乙烯 （PVDF） 及其共聚物 P（VDF-TrFE） 表现出独特的负应变特性。虽然广泛的研究集中在了解这种阴性菌株的起源和机制上，但针对这些特性的努力有限。本研究通过 PbTiO₃ 纳米片和原位静电场的协同作用优化了 P（VDF-TrFE） 压电薄膜的电应变和铁电性能。我们的结果表明，虽然 PbTiO₃ 纳米片的掺入并没有显着增强铁电性，但它显着改善了电应变性能，尤其是负应变，从 -0.097% 增加到 -0.185%，提高了 91%。此外，在 PbTiO₃ 纳米片和原位静电场的共同影响下，P（VDF-TrFE） 的铁电极化和正应变进一步增强，最大极化从 10.79 μC/cm² 增加到 13.16 μC/cm²，提高了 22%，正应变从 0.213% 提高到 0.267%，提高了 25%。我们提出了一种可能的机制来实现这些改进，这归因于在这种协同效应下，非晶相的柔韧性增强和 P（VDF-TrFE） 薄膜中极性β相含量的增加。这项工作重点介绍了控制 P（VDF-TrFE） 压电薄膜的电应变和铁电性能的新策略。