Spin-Glass State above Room Temperature in a Layered Nickelate Lan+1NinO3n+1

Oxide interfaces provide a fertile ground for new forms of magnetic textures that arise from different symmetry constraints, proximity effects, and charge transfer. Here, a room-temperature spin glass state stabilized in heterostructures of the ferromagnetic metallic oxide La2/3Sr1/3MnO3 (LSMO) and the layered Lan+1NinO3n+1 (L-LNO) is reported. Electron energy loss spectra and depth-profile X-ray photoelectron spectroscopy reveal the interfacial electron transfer from Mn3+ to localized Ni3+ states. Density functional theory calculations indicate that charge transfer drives the enhancement of ferromagnetic exchange interaction in the nickelate, leading to the formation of local magnetic order. The room temperature spin-glass state in this artificially engineered LSMO/L-LNO bilayer structure affords opportunities for designing emergent topological spin textures and spintronic devices.