The emergence of magnetic ordering at complex oxide interfaces tuned by defects
Daesung Park, A. D. Rata, I. V. Maznichenko, S. Ostanin, Yulin Gan, Stefano Agrestini, Gregory J. Rees, Marc Walker, Junjie Li, Javier Herrero‐Martín, Gyanendra Singh, Zheng‐Dong Luo, Akash Bhatnagar, Yunzhong Chen, Vasiliki Tileli, Paul Muralt, Alexei Kalaboukhov, Ingrid Mertig, K. Dörr, A. Ernst, Nini Pryds
Abstract
Abstract Complex oxides show extreme sensitivity to structural distortions and defects, and the intricate balance of competing interactions which emerge at atomically defined interfaces may give rise to unexpected physics. In the interfaces of non-magnetic complex oxides, one of the most intriguing properties is the emergence of magnetism which is sensitive to chemical defects. Particularly, it is unclear which defects are responsible for the emergent magnetic interfaces. Here, we show direct and clear experimental evidence, supported by theoretical explanation, that the B-site cation stoichiometry is crucial for the creation and control of magnetism at the interface between non-magnetic ABO 3 -perovskite oxides, LaAlO 3 and SrTiO 3 . We find that consecutive defect formation, driven by atomic charge compensation, establishes the formation of robust perpendicular magnetic moments at the interface. Our observations propose a route to tune these emerging magnetoelectric structures, which are strongly coupled at the polar-nonpolar complex oxide interfaces.