Spinterface-Induced Modification in Magnetic Properties in Co₄₀Fe₄₀B₂₀/Fullerene Bilayers

Abstract

Organic semiconductor/ferromagnetic bilayer thin films can exhibit novel properties due to the formation of spinterface at the interface. Buckminsterfullerene (C60) has been shown to exhibit ferromagnetism at the interface when it is placed next to a ferromagnet (FM) such as Fe or Co. Formation of a spinterface occurs due to the orbital hybridization and spin-polarized charge transfer at the interface. In this work, we have demonstrated that one can enhance the magnetic anisotropy of the low Gilbert damping alloy CoFeB thin film by introducing a C60 layer. We have shown that anisotropy increases by increasing the thickness of C60, which might be a result of the formation of a spinterface. However, the magnetic domain structure remains the same in the bilayer samples as compared to that in the reference CoFeB film.

Spinterface Effects in Hybrid La0.7Sr0.3MnO3/SrTiO3/C60/Co Magnetic Tunnel Junctions

“…The formation of a hybridized layer at the interface between ferromagnetic metals and organic semiconductors has been proven to be efficient in the modulation of the magnetic and spin properties of both components. , An illustrative example is represented by the interface between the pure carbon allotrope buckminsterfullerene (C 60 ) and ferromagnetic 3d metals, − such as Co. Orbital hybridization at the interface between a C 60 overlayer and an epitaxial ultrathin film of Co(0001) leads to a considerable change in the magnetic anisotropy of the Co, able to induce a magnetization reorientation transition from in-plane to out-of-plane in the ferromagnetic layer and a magnetic hardening . Correspondingly, the nonmagnetic C 60 molecule is also modified, becoming spin active by acquiring a net magnetic moment as a consequence of coupling of the carbon atoms closest to the underlying Co.…”