Ion-Irradiation-Induced Cobalt/Cobalt Oxide Heterostructures: Printing 3D Interfaces

Autor: Yıldırım, Oğuz, Hilliard, Donovan, Arekapudi, Sri Sai Phani Kanth, Fowley, Ciarán, Cansever, Hamza, Koch, Leopold, Ramasubramanian, Lakshmi, Zhou, Shengqiang, Böttger, Roman, Lindner, Jürgen, Faßbender, Jürgen, Hellwig, Olav, Deac, Alina M.
Rok vydání: 2020
Předmět:
Zdroj: ACS Applied Materials and Interfaces (2020)
Druh dokumentu: Working Paper
DOI: 10.1021/acsami.9b13503
Popis: 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 form 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 the reduction from insulating, non-ferromagnetic cobalt oxides to metallic cobalt. Metallic cobalt 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-confined-path based current perpendicular-to-plane giant magnetoresistance read-heads.
Comment: This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials and Interfaces copyright \c{opyright} American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https:// pubs.acs.org/articlesonrequest/AOR-rPGr2e7nZ7tzzwK3tnBZ
Databáze: arXiv