Ion-irradiation-induced cobalt/cobalt oxide heterostructures: printing 3D interfaces
Ion-irradiation-induced cobalt/cobalt oxide heterostructures: printing 3D interfaces
Yildirim, O.; Hilliard, D.; Arekapudi, S. S. P. K.; Fowley, C.; Cansever, H.; Koch, L.; Ramasubramanian, L.; Zhou, S.; Böttger, R.; Lindner, J.; Faßbender, J.; Hellwig, O.; Deac, A. M.
Abstract
Interfaces separating ferromagnetic (FM) layers from non-ferromagnetic layers offer unique properties due to spin-orbit coupling and symmetry breaking, yielding effects such as exchange bias, perpendicular magnetic anisotropy, spin-pumping, spin-transfer torques, conversion between charge and spin currents and vice-versa. These interfacial phenomena play crucial roles for magnetic data storage and transfer applications, which require forming FM nano-structures embedded in non-ferromagnetic matrices. Here, we investigate the possiblity of creating such nano-structures by ion-irradiation. We study the effect of lateral confinement on the ion-irradiation-induced reduction of non-magnetic metal oxides (e.g., antiferro- or paramagnetic) to ferromagnetic metals. Our findings are later exploited to form 3-dimensional magnetic interfaces between Co, CoO and Pt by spatially-selective irradiation of CoO/Pt multilayers. We demonstrate that the mechanical displacement of the O atoms plays a crucial role during their reduction from insulating, non-ferromagnetic Co oxides to metallic Co. Metallic Co yields both perpendicular magnetic anisotropy in the generated Co/Pt nano-structures, and, at low temperatures, exchange bias at vertical interfaces between Co and CoO. If pushed to the limit of ion-irradiation technology, this approach could, in principle, enable the creation of densely-packed, atomic scale ferromagnetic point-contact spin-torque oscillator (STO) networks, or conductive channels for current-conned-path based current perpendicular-to-plane giant magnetoresistance read-heads.
Keywords: ion; irradiation; proton; cobalt oxide; CoO; Co3O4; paramagnetic; ferromagnetic; reduction; removal; oxygen; displacement; exchange; bias; magnetization; antiferromagnetic; perpencular; magnetic; anisotropy
Beteiligte Forschungsanlagen
- Ionenstrahlzentrum DOI: 10.17815/jlsrf-3-159
Verknüpfte Publikationen
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 30366) publication
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ACS Applied Materials and Interfaces 12(2020)8, 9858-9864
DOI: 10.1021/acsami.9b13503
Cited 5 times in Scopus
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