论文标题
弹性铁电$ batio_3 $ membranes中的巨型超弹性压电
Giant Superelastic Piezoelectricity in Flexible Ferroelectric $BaTiO_3$ Membranes
论文作者
论文摘要
常用压电材料中的机械位移通常仅限于线性或双轴，而材料尺寸的几％。在这里，我们表明独立的Batio $ _3 $膜表现出非惯性机电耦合。在外部电场下，这些超弹性膜经历可控和可逆的“寿司 - 滚动式” 180 $^\ circ $折叠式循环。这种无折痕的折叠是由带电的铁电域介导的，在室温下为30 nm厚的膜和60 $^\ Circ $ C的巨型> 3.8和4.6 $ $ M的位移。进一步增加电场高于强制性值，改变了折叠曲率，从而增加了有效的压电响应。最后，发现膜随温度升高，然后在居里温度上方完全固定膜，从而使我们能够对效应的铁电域起源进行建模。
Mechanical displacement in commonly used piezoelectric materials is typically restricted to linear or biaxial in nature and to a few percent of the material dimensions. Here, we show that free-standing BaTiO$_3$ membranes exhibit non-conventional electromechanical coupling. Under an external electric field, these superelastic membranes undergo controllable and reversible 'sushi-rolling-like' 180$^\circ$ folding-unfolding cycles. This crease-free folding is mediated by charged ferroelectric domains, leading to a giant > 3.8 and 4.6 $μ$m displacements for a 30-nm thick membrane at room temperature and 60$^\circ$C, respectively. Further increasing the electric field above the coercive value changes the fold curvature, hence augmenting the effective piezoresponse. Finally, it is found that the membranes fold with increasing temperature followed by complete immobility of the membrane above the Curie temperature, allowing us to model the ferroelectric-domain origin of the effect.
