Spinterface-Mediated Magnetic Properties of Nanoscale-Thick Co₂₀Fe₆₀B₂₀/Alq₃ Heterostructures for Spintronic Applications

Organic semiconductors (OSCs) are suitable materials for spintronic applications as they can form a “ spinterface ” when placed next to a ferromagnetic layer, which in turn leads to emerging functionalities. The electronic interactions across the interface can impact the overall magnetic anisotropy, the magnetization reversal, and the magnetization dynamics of the ferromagnet/OSC heterostructure. Planar tris(8-hydroxy- quinoline)aluminum (Alq 3 ) OSC has shown tremendous potential for spintronics applications thanks to its efficient spin-polarized current transport ability. Here, we study the effects of the hybrid interface formed at the nanoscale when Alq 3 molecules are deposited onto a native amorphous ferromagnet Co 20 Fe 60 B 20 (CFB) layer. The π- d hybridization in CFB/Alq 3 enhances the coercive field and significantly modifies the shape and size of the magnetic domains. An ∼86% increase in uniaxial anisotropic energy and a reduction in magnetic damping are also evidence of the formation of interfacial hybrid states. The noncollinear density functional theory calculations on the proximal model systems show a modification in the local magnetic anisotropies due to molecular decoration in the model ferromagnetic substrates.