Magnetic Properties of bcc-Fe(001)/C₆₀ Interfaces for Organic Spintronics

The magnetic structure of the interfaces between organic semiconductors and ferromagnetic contacts plays a key role in the spin injection and extraction processes in organic spintronic devices. We present a combined computational (density functional theory) and experimental (X-ray magnetic circular dichroism) study on the magnetic properties of interfaces between bcc-Fe(001) and C(60) molecules. C(60) is an interesting candidate for application in organic spintronics due to the absence of hydrogen atoms and the associated hyperfine fields. Adsorption of C(60) on Fe(001) reduces the magnetic moments on the top Fe layers by ∼6%, while inducing an antiparrallel magnetic moment of ∼-0.2 μ(B) on C(60). Adsorption of C(60) on a model ferromagnetic substrate consisting of three Fe monolayers on W(001) leads to a different structure but to very similar interface magnetic properties.