Transparent ferroelectric crystals with ultrahigh piezoelectricity
Transparent ferroelectric crystals with ultrahigh piezoelectricity
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DOI：
10.1038/s41586-019-1891-y
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发表时间：
2020-01-16
期刊：
影响因子：
64.8
通讯作者：
Li, Fei
中科院分区：
文献类型：
--
作者：
Qiu, Chaorui;Wang, Bo;Li, Fei
透明压电体对于范围从光声成像换能器到用于触觉应用的透明致动器的许多混合超声-光学装置是高度期望的（1-7）。然而，同时实现高压电性和完美的透明度是具有挑战性的，因为大多数高性能压电体是包含高密度光散射畴壁的铁电体。在这里，通过相场模拟和实验相结合，我们展示了一个相对简单的方法，使用交流电场工程原本不透明的菱形铅的畴结构（Mg 1/3 Nb 2/3）O-3-PbTiO 3（PMN-PT）晶体，以同时产生近乎完美的透明性，（大于2，100皮库仑/牛顿）、优异的机电耦合系数k（33）（约94%）和大的电光系数γ（33）（约220皮米/伏），这远远超出了常用的透明铁电晶体LiNbO 3的性能。我们发现，增加畴尺寸导致[001]取向的菱面体PMN-PT晶体的d（33）值更高，挑战了减小畴尺寸总是导致更高压电性的传统观点（8-10）。这项工作提出了一种通过铁电畴工程实现高透明度和压电性的范例，我们期望这里报道的透明铁电晶体为广泛的混合器件应用提供一条途径，例如医学成像，自能量采集触摸屏和隐形机器人设备。
Transparent piezoelectrics are highly desirable for numerous hybrid ultrasound-optical devices ranging from photoacoustic imaging transducers to transparent actuators for haptic applications(1-7). However, it is challenging to achieve high piezoelectricity and perfect transparency simultaneously because most high-performance piezoelectrics are ferroelectrics that contain high-density light-scattering domain walls. Here, through a combination of phase-field simulations and experiments, we demonstrate a relatively simple method of using an alternating-current electric field to engineer the domain structures of originally opaque rhombohedral Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMN-PT) crystals to simultaneously generate near-perfect transparency, an ultrahigh piezoelectric coefficient d(33) (greater than 2,100 picocoulombs per newton), an excellent electromechanical coupling factor k(33) (about 94 per cent) and a large electro-optical coefficient gamma(33) (approximately 220 picometres per volt), which is far beyond the performance of the commonly used transparent ferroelectric crystal LiNbO3. We find that increasing the domain size leads to a higher d(33) value for the [001]-oriented rhombohedral PMN-PT crystals, challenging the conventional wisdom that decreasing the domain size always results in higher piezoelectricity(8-10). This work presents a paradigm for achieving high transparency and piezoelectricity by ferroelectric domain engineering, and we expect the transparent ferroelectric crystals reported here to provide a route to a wide range of hybrid device applications, such as medical imaging, self-energy-harvesting touch screens and invisible robotic devices.