Braiding Lateral Morphotropic Grain Boundary in Homogeneitic Oxides

Interfaces formed by correlated oxides offer a critical avenue for discovering emergent phenomena and quantum states. However, the fabrication of oxide interfaces with variable crystallographic orientations and strain states integrated along a film plane is extremely challenge by conventional layer-by-layer stacking or self-assembling. In this talk, we will discuss the creation of morphotropic grain boundaries (GBs) in laterally interconnected cobaltite [1] and manganite [2] homostructures. Single-crystalline substrates and suspended ultrathin freestanding membranes provide independent templates for coherent epitaxy and constraint on the growth orientation, resulting in seamless and atomically sharp GBs. Electronic states and magnetic behavior in hybrid structures are laterally modulated and isolated by GBs, enabling artificially engineered functionalities in the planar matrix. Using this method, we are able to creat magnetic nanoislands with minimum size of ~35 nm in diameter, suggesting the highest possible areal density could reach upto ~ 400 Gbit/in² [3]. Our work offers a simple and scalable method for fabricating unprecedented innovative interfaces through controlled synthesis routes as well as provides a platform for exploring potential applications in neuromorphics, solid state batteries, and catalysis.<br/>[1] S. R. Chen, et al., Adv. Mater. 35, 2206961 (2023).<br/>[2] Y. Wang, et al., Nano Res. 16, 7829–7836 (2023).<br/>[3] S. R. Chen, et al., Adv. Funct. Mater. 33, 2302936 (2023).