Department of Materials Science and Engineering, Drexel University , Philadelphia, Pennsylvania, United States.
ACS Nano. 2014 Jan 28;8(1):894-903. doi: 10.1021/nn405636c. Epub 2013 Dec 16.
Magnetoelectric oxide heterostructures are proposed active layers for spintronic memory and logic devices, where information is conveyed through spin transport in the solid state. Incomplete theories of the coupling between local strain, charge, and magnetic order have limited their deployment into new information and communication technologies. In this study, we report direct, local measurements of strain- and charge-mediated magnetization changes in the La0.7Sr0.3MnO3/PbZr0.2Ti0.8O3 system using spatially resolved characterization techniques in both real and reciprocal space. Polarized neutron reflectometry reveals a graded magnetization that results from both local structural distortions and interfacial screening of bound surface charge from the adjacent ferroelectric. Density functional theory calculations support the experimental observation that strain locally suppresses the magnetization through a change in the Mn-eg orbital polarization. We suggest that this local coupling and magnetization suppression may be tuned by controlling the manganite and ferroelectric layer thicknesses, with direct implications for device applications.
磁电氧化物异质结构被提议作为自旋电子学存储器和逻辑器件的活性层，其中信息通过固态中的自旋输运来传递。局部应变、电荷和磁有序之间的耦合的不完全理论限制了它们在新的信息和通信技术中的应用。在这项研究中，我们使用实空间和倒空间中的空间分辨特性技术，报告了 La0.7Sr0.3MnO3/PbZr0.2Ti0.8O3 体系中应变和电荷介导的磁化变化的直接、局部测量。极化中子反射率揭示了一种梯度磁化，这是由局部结构变形和相邻铁电体的束缚表面电荷的界面屏蔽共同作用的结果。密度泛函理论计算支持实验观察到的应变通过 Mn-eg 轨道极化的变化局部抑制了磁化。我们认为，通过控制锰酸盐和铁电体层的厚度，可以调节这种局部耦合和磁化抑制，这对器件应用有直接的影响。
