Magnetic Proximity Effect in Pt/CoFe2O4 Bilayers

Abstract

We observe the magnetic proximity effect (MPE) in Pt/CoFe2O4 bilayers grown by molecular beam epitaxy. This is revealed through angle-dependent magnetoresistance measurements at 5 K, which isolate the contributions of induced ferromagnetism (i.e. anisotropic magnetoresistance) and spin Hall effect (i.e. spin Hall magnetoresistance) in the Pt layer. The observation of induced ferromagnetism in Pt via AMR is further supported by density functional theory calculations and various control measurements including insertion of a Cu spacer layer to suppress the induced ferromagnetism. In addition, anomalous Hall effect measurements show an out-of-plane magnetic hysteresis loop of the induced ferromagnetic phase with larger coercivity and larger remanence than the bulk CoFe2O4. By demonstrating MPE in Pt/CoFe2O4, these results establish the spinel ferrite family as a promising material for MPE and spin manipulation via proximity exchange fields.

16 pages, 6 figures

References in corpus (7)

• Theory of spin Hall magnetoresistance
• Proximity-induced ferromagnetism in graphene revealed by anomalous Hall effect
• Spin transport in proximity induced ferromagnetic graphene
• Magnetic Insulator-Induced Proximity Effects in Graphene: Spin Filtering and Exchange Splitting Gaps
• Room temperature spin filtering in epitaxial cobalt-ferrite tunnel barriers
• Above 400 K Robust Perpendicular Ferromagnetic Phase in a Topological Insulator
• Anomalous Hall hysteresis in Tm3Fe5O12/Pt with strain-induced perpendicular magnetic anisotropy