Claudiu LucoveiNational Institute of Materials Physics (NIMP), Atomistilor Street 405A, 077125 Magurele, Romania; Faculty of Physics, R&D Center for Materials and Electronic & Optoelectronic Devices (MDEO), University of Bucharest, Atomistilor Street 405, 077125 Magurele, Romania;
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Nicolae FilipoiuFaculty of Physics, R&D Center for Materials and Electronic & Optoelectronic Devices (MDEO), University of Bucharest, Atomistilor Street 405, 077125 Magurele, Romania
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Andrei KuncserNational Institute of Materials Physics (NIMP), Atomistilor Street 405A, 077125 Magurele, Romania
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Anda-Elena StanciuNational Institute of Materials Physics (NIMP), Atomistilor Street 405A, 077125 Magurele, Romania
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Piraux, LucUCLouvain
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Vlad-Andrei AntoheFaculty of Physics, R&D Center for Materials and Electronic & Optoelectronic Devices (MDEO), University of Bucharest, Atomistilor Street 405, 077125 Magurele, Romania; Université catholique de Louvain (UCLouvain), Institute of Condensed Matter and Nanosciences (IMCN), Croix du Sud 1, B-1348 Louvain-la-Neuve, Belgium;
We report the facile and low-cost preparation as well as detailed characterization of dense arrays of passivated ferromagnetic nickel (Ni) nanotubes (NTs) vertically-supported onto solid Au-coated Si substrates. The proposed fabrication method relies on electrochemical synthesis within the nanopores of a supported anodic aluminum oxide (AAO) template and allows for fine tuning of the NTs ferromagnetic walls just by changing the cathodic reduction potential during the nanostructures’ electrochemical growth. Subsequently, the experimental platform allowed further passivation of the Ni NTs with the formation of ultra-thin antiferromagnetic layers of nickel oxide (NiO). Using adequately adapted magnetic measurements, we afterwards demonstrated that the thickness of the NT walls and of the thin antiferromagneticNiO layer, strongly influences the magnetic behavior of the dense array of exchange-coupled Ni/NiO NTs. The specific magnetic properties of these hybrid ferromagnetic/antiferromagnetic nanosystems were then correlated with the morpho-structural and geometrical parameters of the NTs, as well as ultimately strengthened by additionally-implemented micromagnetic simulations. The effect of the unidirectional anisotropy strongly amplified by the cylindrical geometry of the ferromagnetic/antiferromagnetic interfaces has been investigated with the magnetic field applied both parallel and perpendicular to the NTs axis.
Claudiu Lucovei, Nicolae Filipoiu, Andrei Kuncser, Anda-Elena Stanciu, Stefan Antohe, Camelia-Florina Florica, Andreea Costas, Ionut Enculescu, Piraux, L., Victor Kuncser, & Vlad-Andrei Antohe. (2020). Unidirectional Magnetic Anisotropy in Dense Vertically-Standing Arrays of Passivated Nickel Nanotubes. Nanomaterials, 10(2444), 10. https://doi.org/10.3390/nano10122444 (Original work published 2020)