Emerging ferromagnetic phase in self-assembled mixed valence manganite nanowires

Nanoscale magnetism in oxides with the lateral size down to 300 nm is critical for scientific investigation and advanced technological applications such as spintronics, but often complicated to fabricate. Specifically, the emergent magnetic phenomena induced by the size effect attract tremendous attention. In this situation, fabrication of self-assembled nanoarchitectures in complex oxides and strategically modulating their properties are urgently needed. Here, we report the emerging single ferromagnetic phase state in self-assembled nanowires on the thin film surface of mixed valence manganite La_0.5Sr_0.5MnO₃, by using low temperature magnetic force microscopy. The ferromagnetic state can be reversely switched in the presence of an external magnetic field. This work paves the way for manipulating the phase coexistence state without an external field and provides insight into the size limitation for designing next generation electronic and spintronic devices in complex oxide systems.