Dost, R. orcid.org/0000-0002-8578-0389, Zhou, Y., Zhang, H. et al. (2 more authors) (2020) Effect of annealing on the electrical and magnetic properties of electrodeposited Ni and permalloy nanowires. Journal of Magnetism and Magnetic Materials, 499. 166276. ISSN 0304-8853
Abstract
The influence of annealing on the microstructure and the electrical and magnetic properties of cylindrical nickel-based nanowires has been investigated. Nanowires of nickel of ~275 nm diameter and of permalloy (Py) of ~70 nm diameter were fabricated by electrochemical deposition into nanoporous templates of polycarbonate and anodic alumina, respectively. Characterization was carried out on as-grown and up to 650 °C heat-treated nanowires. Transmission electron microscopy imaging and diffraction of the nanowires showed a temperature-correlated grain growth of an initially nanocrystalline structure (untreated) with <8 nm (Ni) and <20 nm (Py) grains towards coarser poly-crystallinity after heat treatment with grains up to ~160 nm (Ni) and ~70 nm (Py), the latter being limited by the nanowire width. The electrical conductivity of individual as-grown and 650 °C annealed Ni nanowires was measured in-situ by scanning electron microscopy. At low current densities, the conductivity of annealed nanowires was estimated to have doubled over as-grown nanowires. We attribute this increase to the observed grain growth. The annealed nanowire was subsequently subjected to increasing current densities. Above 120 kA.mm−2 the nanowire resistance started to rise. At 450 kA.mm−2, the nanowire melted and current flow ceased. Magnetometry of as-grown and annealed nanowire arrays showed them to display quasi-thin film magnetic properties. Coercivity and saturation field were inversely correlated in annealed wires and a 25% tunability in these properties was achieved at just 200 °C.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 Elsevier B.V. This is an author-produced version of a paper subsequently published in Journal of Magnetism and Magnetic Materials. Uploaded in accordance with the publisher's self-archiving policy. Article available under the terms of the CC-BY-NC-ND licence (https://creativecommons.org/licenses/by-nc-nd/4.0/). |
Keywords: | electrodeposited magnetic nanowires; annealing; permalloy nanowires; crystallinity; conductivity; coercivity |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Materials Science and Engineering (Sheffield) The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Funding Information: | Funder Grant number ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/L020696/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 06 Mar 2020 13:58 |
Last Modified: | 11 Dec 2020 01:38 |
Status: | Published |
Publisher: | Elsevier BV |
Refereed: | Yes |
Identification Number: | 10.1016/j.jmmm.2019.166276 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:154679 |