Since the concept of “multiferroic” was first proposed in 1968, the coupling effect between different ferroic orders has attracted great interest in energy, information, and biomedical fields. However, the fully ferroelectric–fully ferroelastic effect has never been experimentally observed in hybrid perovskites, even though this effect was predicted to exist half a century ago. Realizing such cross-linking effects of polarization vectors and strain tensors has always been a huge challenge because of the complex difference in these two ferroic origins. Here, we report a multiferroic with full ferroelectricity and full ferroelasticity in two-dimensional (2D) hybrid perovskites based on ferroelectrochemistry. The dynamic molecular reorientations endow (cyclohexanemethylaminium)₂PbCl₄ with a desired symmetry change of 4̅2mFmm2 at a Curie temperature of 411.8 K. More strikingly, the switchable evolution of ferroelastic domains was directly observed under the control of either electric or mechanical fields, which is the first experimental observation of a fully ferroelectric–fully ferroelastic effect in hybrid perovskites. This work would provide new insights into understanding the intrinsic cross-linking mechanism between ferroelectricity and ferroelasticity toward the development of multichannel interactive microelectronic devices.

中文翻译：

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多铁杂化钙钛矿中全铁电-全铁弹性效应的实验观察


自1968年“多铁性”概念首次提出以来，不同铁性有序之间的耦合效应引起了能源、信息和生物医学领域的极大兴趣。然而，尽管半个世纪前就预测这种效应存在，但从未在杂化钙钛矿中实验观察到全铁电-全铁弹效应。由于这两种铁离子起源的复杂差异，实现偏振矢量和应变张量的这种交联效应一直是一个巨大的挑战。在这里，我们报告了基于铁电化学的二维（2D）杂化钙钛矿中具有全铁电性和全铁弹性的多铁性。动态分子重新取向赋予（环己烷甲基胺） ₂ PbCl ₄ 在 411.8 K 的居里温度下具有所需的 4̅2mFmm2 对称性变化。更引人注目的是，直接观察到铁弹性域的可切换演化在电场或机械场的控制下，这是杂化钙钛矿中全铁电-全铁弹性效应的首次实验观察。这项工作将为理解铁电性和铁弹性之间的内在交联机制提供新的见解，从而促进多通道交互式微电子器件的发展。