Irwin J, Lindemann S, Maeng W, Wang J J, Vaithyanathan V, Hu J M, Chen L Q, Schlom D G, Eom C B, Rzchowski M S
Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin, 53706, United States.
Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin, 53706, United States.
Sci Rep. 2019 Dec 16;9(1):19158. doi: 10.1038/s41598-019-55139-1.
Strain-coupled magnetoelectric (ME) phenomena in piezoelectric/ferromagnetic thin-film bilayers are a promising paradigm for sensors and information storage devices, where strain manipulates the magnetization of the ferromagnetic film. In-plane magnetization rotation with an electric field across the film thickness has been challenging due to the large reduction of in-plane piezoelectric strain by substrate clamping, and in two-terminal devices, the requirement of anisotropic in-plane strain. Here we show that these limitations can be overcome by designing the piezoelectric strain tensor using the boundary interaction between biased and unbiased piezoelectric. We fabricated 500 nm thick, (001) oriented [Pb(MgNb)O]-[PbTiO] (PMN-PT) unclamped piezoelectric membranes with ferromagnetic Ni overlayers. Guided by analytical and numerical continuum elastic calculations, we designed and fabricated two-terminal devices exhibiting electric field-driven Ni magnetization rotation. We develop a method that can apply designed strain patterns to many other materials systems to control properties such as superconductivity, band topology, conductivity, and optical response.
压电/铁磁薄膜双层中的应变耦合磁电（ME）现象是传感器和信息存储设备的一个有前景的范例，其中应变可操控铁磁薄膜的磁化强度。由于衬底夹持导致面内压电应变大幅降低，以及在两端器件中对各向异性面内应变的要求，利用薄膜厚度方向的电场实现面内磁化强度旋转一直具有挑战性。在此，我们表明通过利用偏置和非偏置压电体之间的边界相互作用来设计压电应变张量，可以克服这些限制。我们制备了500纳米厚、（001）取向的[Pb（MgNb）O]-[PbTiO]（PMN-PT）未夹持压电薄膜，并覆盖了铁磁镍层。在解析和数值连续弹性计算的指导下，我们设计并制备了展现电场驱动镍磁化强度旋转的两端器件。我们开发了一种方法，该方法可将设计好的应变模式应用于许多其他材料体系，以控制诸如超导性、能带拓扑、导电性和光学响应等性质。
