Ferromagnetic and Antiferromagnetic Coupling of Spin Molecular Interfaces with High Thermal Stability

Abstract

We report an advanced organic spin-interface architecture with magnetic remanence at room temperature, constituted by metal phthalocyanine molecules magnetically coupled with Co layer(s), mediated by graphene. Fe- and Cu-phthalocyanines assembled on graphene/Co have identical structural configurations, but FePc couples antiferromagnetically with Co up to room temperature, while CuPc couples ferromagnetically with weaker coupling and thermal stability, as deduced by element-selective X-ray magnetic circular dichroic signals. The robust antiferromagnetic coupling is stabilized by a superexchange interaction, driven by the out-of-plane molecular orbitals responsible of the magnetic ground state and electronically decoupled from the underlying metal via the graphene layer, as confirmed by ab initio theoretical predictions. These archetypal spin interfaces can be prototypes to demonstrate how antiferromagnetic and/or ferromagnetic coupling can be optimized by selecting the molecular orbital symmetry.

arXiv commentThis document is the Accepted Manuscript version of a Published Work that appeared in final form in Nano. Lett. copyright American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/acs.nanolett.7b04836

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Cited by in corpus (7)

• Narrowing of d bands of FeCo layers intercalated under graphene
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• Roughness-induced magnetic decoupling at organic-inorganic interface
• Proximity Effect of Epitaxial Iron Phthalocyanine Molecules on High-Quality Graphene Devices
• The role of rare-earth atoms in the anisotropy and antiferromagnetic exchange coupling at a hybrid metal-organic interface
• Graphene decoupling through oxygen intercalation on Gr/Co and Gr/Co/Ir interfaces