Physics Department, Faculty of Science, Helwan University, Helwan, Cairo, 11798, Egypt.
Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569, Stuttgart, Germany.
Sci Rep. 2023 Mar 8;13(1):3847. doi: 10.1038/s41598-023-30814-6.
Interface engineering in complex oxide superlattices is a growing field, enabling manipulation of the exceptional properties of these materials, and also providing access to new phases and emergent physical phenomena. Here we demonstrate how interfacial interactions can induce a complex charge and spin structure in a bulk paramagnetic material. We investigate a superlattice (SLs) consisting of paramagnetic LaNiO (LNO) and highly spin-polarized ferromagnetic LaCaMnO (LCMO), grown on SrTiO (001) substrate. We observed emerging magnetism in LNO through an exchange bias mechanism at the interfaces in X-ray resonant magnetic reflectivity. We find non-symmetric interface induced magnetization profiles in LNO and LCMO which we relate to a periodic complex charge and spin superstructure. High resolution scanning transmission electron microscopy images reveal that the upper and lower interfaces exhibit no significant structural variations. The different long range magnetic order emerging in LNO layers demonstrates the enormous potential of interfacial reconstruction as a tool for tailored electronic properties.
界面工程在复杂氧化物超晶格中是一个正在发展的领域，它可以控制这些材料的特殊性能，也可以获得新的相和涌现的物理现象。在这里，我们展示了界面相互作用如何在顺磁体材料中诱导出复杂的电荷和自旋结构。我们研究了一种由顺磁 LaNiO (LNO) 和高度自旋极化的铁磁 LaCaMnO (LCMO) 组成的超晶格 (SLs)，生长在 SrTiO (001) 衬底上。我们通过 X 射线共振磁反射测量在界面处观察到交换偏置机制引起的 LNO 中出现的磁性。我们发现 LNO 和 LCMO 中的界面诱导磁化分布是非对称的，我们将其与周期性的复杂电荷和自旋超结构联系起来。高分辨率扫描透射电子显微镜图像显示，上下界面没有明显的结构变化。在 LNO 层中出现的不同长程磁有序证明了界面重构作为一种定制电子性质的工具具有巨大的潜力。
