Alasadi, A., Claeyssens, F. orcid.org/0000-0002-1030-939X and Allwood, D.A. (2018) Laser direct writing (LDW) of magnetic structures. AIP Advances, 8 (5). 056322. ISSN 2158-3226
Abstract
Laser direct writing (LDW) has been used to pattern 90nm thick permalloy (Ni 81 Fe 19 ) into 1-D and 2-D microstructures with strong shape anisotropy. Sub-nanosecond laser pulses were focused with a 0.75 NA lens to a 1.85μm diameter spot, to achieve a fluence of approximately 350 mJ.cm -2 and ablate the permalloy film. Computer-controlled sample scanning then allowed structures to be defined. Scan speeds were controlled to give 30% overlap between successive laser pulses and reduce the extent of width modulation in the final structures. Continuous magnetic wires that adjoined the rest of the film were fabricated with widths from 650 nm - 6.75μm and magneto-optical measurements showed coercivity reducing across this width range from 47 Oe to 11 Oe. Attempts to fabricate wires narrower than 650nm resulted in discontinuities in the wires and a marked decrease in coercivity. This approach is extremely rapid and was carried out in air, at room temperature and with no chemical processing. The 6-kHz laser pulse repetition rate allowed wire arrays across an area of 4 mm x 0.18 mm to be patterned in 85 s.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2018 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
Keywords: | Magnetic properties; Optical imaging; Ferromagnetic materials; Laser ablation; Magnetic materials; Thin films; Kerr effects; Lenses; Chemical processes; Alloys |
Dates: |
|
Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Materials Science and Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 31 Jan 2018 12:46 |
Last Modified: | 09 Apr 2024 08:05 |
Status: | Published |
Publisher: | AIP Publishing |
Refereed: | Yes |
Identification Number: | 10.1063/1.5007227 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:126864 |