Disentangling magnetic hardening and molecular spin chain contributions to exchange bias in ferromagnet/molecule bilayers

Abstract

We performed SQUID and FMR magnetometry experiments to clarify the relationship between two reported magnetic exchange effects arising from interfacial spin-polarized charge transfer within ferromagnetic metal (FM)/molecule bilayers: the magnetic hardening effect, and spinterface-stabilized molecular spin chains. To disentangle these effects, both of which can affect the FM magnetization reversal, we tuned the metal phthalocyanine molecule central site's magnetic moment to selectively enhance or suppress the formation of spin chains within the molecular film. We find that both effects are distinct, and additive. In the process, we 1) extended the list of FM/molecule candidate pairs that are known to generate magnetic exchange effects, 2) experimentally confirmed the predicted increase in anisotropy upon molecular adsorption; and 3) showed that spin chains within the molecular film can enhance magnetic exchange. This magnetic ordering within the organic layer implies a structural ordering. Thus, by distengangling the magnetic hardening and exchange bias contributions, our results confirm, as an echo to progress regarding inorganic spintronic tunnelling, that the milestone of spintronic tunnelling across structurally ordered organic barriers has been reached through previous magnetotransport experiments. This paves the way for solid-state devices studies that exploit the quantum physical properties of spin chains, notably through external stimuli.

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References in corpus (5)

• Unravelling the role of the interface for spin injection into organic semiconductors
• Spin- and energy-dependent tunneling through a single molecule with intramolecular spatial resolution
• Molecular Thin Films: a New Type of Magnetic Switch
• Coercivity and random interfacial exchange coupling in CoPt/Co films
• Nanosized Vertical Organic Spin-Valves

Cited by in corpus (6)

• Exchange bias in molecule/Fe3GeTe2 van der Waals heterostructures via spinterface effects
• Influence of Atomic Roughness at The Uncompensated Fe/CoO (111) Interface on Exchange Bias Effect
• A theoretical perspective on the modification of the magnetocrystalline anisotropy at molecule-cobalt interfaces
• Magnetoresistance and spintronic anisotropy induced by spin excitations along molecular spin chains
• The role of rare-earth atoms in the anisotropy and antiferromagnetic exchange coupling at a hybrid metal-organic interface
• Low-energy, ultrafast spin reorientation at competing hybrid interfaces with tunable operating temperature