Two-dimensional electron gases (2DEGs) formed at the interface between two insulating complex oxides, one of which is SrTiO3 (STO), provide new opportunities for electronics and spintronics due to their high-mobility, superconductivity, interfacial 2D-magnetism, large and tunable spin-orbit coupling, as well as extraordinary spin-charge conversion efficiency. Although there are reports on the possible magnetic ordering in LaAlO3/SrTiO3 (LAO/STO) heterostructures, these samples tend to be insulating or show signatures related to the interaction between itinerant electrons and localized magnetic moments. Herein, I summarized the recent three different approaches towards robust magnetic 2DEGs in STO-based heterostructures: (1) The magnetic proximity effect induced by a EuTiO3 or BaFeO3 ferromagnetic buffer layer at the LAO/STO interface, 1, 2 where the spin polarization emerges below T=10 K; (2) The introduction of the ferromagnetism into the top layer of LAO by magnetic doping or the introduction of a ferromagnetic capping layer directly on STO as demonstrated in the cases of the magnetic diluted oxide interface of LAMO/STO3, and MAl2O4 (M=Ni, Co)/STO4, respectively; (3) The conventional approach by doping STO substrate with magnetic ions, such as the magnetic 2DEGs observed at a LAO/Fe-doped-STO interface5 which shows anomalous Hall effect up to room temperature. Besides, both the LAO/EuTiO3/STO and LAMO/STO systems show signatures of the coexistence of ferromagnetism and superconductivity, although their carriers come from two-band and single band conduction respectively.
|Conference||4th Functional Oxide Thin Films for Advanced Energy and Information Technology Conference,|
|Period||17/07/2019 → 20/07/2019|