Cargando…
Use of Two-Photon Lithography with a Negative Resist and Processing to Realise Cylindrical Magnetic Nanowires
Cylindrical magnetic nanowires have been shown to exhibit a vast array of fascinating spin textures, including chiral domains, skyrmion tubes, and topologically protected domain walls that harbor Bloch points. Here, we present a novel methodology that utilizes two-photon lithography in order to real...
Autores principales: | , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2020
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7152837/ https://www.ncbi.nlm.nih.gov/pubmed/32121262 http://dx.doi.org/10.3390/nano10030429 |
_version_ | 1783521558991470592 |
---|---|
author | Askey, Joseph Hunt, Matthew Oliver Langbein, Wolfgang Ladak, Sam |
author_facet | Askey, Joseph Hunt, Matthew Oliver Langbein, Wolfgang Ladak, Sam |
author_sort | Askey, Joseph |
collection | PubMed |
description | Cylindrical magnetic nanowires have been shown to exhibit a vast array of fascinating spin textures, including chiral domains, skyrmion tubes, and topologically protected domain walls that harbor Bloch points. Here, we present a novel methodology that utilizes two-photon lithography in order to realize tailored three-dimensional (3D) porous templates upon prefabricated electrodes. Electrochemical deposition is used to fill these porous templates, and reactive ion etching is used to free the encased magnetic nanowires. The nanowires are found to have a diameter of 420 nm, length of 2.82 μm, and surface roughness of 7.6 nm. Magnetic force microscopy in an externally applied field suggests a complex spiraling magnetization state, which demagnetizes via the production of vortices of alternating chirality. Detailed micro-magnetic simulations confirm such a state and a qualitative agreement is found with respect to the switching of experimental nanowires. Surprisingly, simulations also indicate the presence of a Bloch point as a metastable state during the switching process. Our work provides a new means to realize 3D magnetic nanowires of controlled geometry and calculations suggest a further reduction in diameter to sub-200 nm will be possible, providing access to a regime of ultrafast domain wall motion. |
format | Online Article Text |
id | pubmed-7152837 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-71528372020-04-20 Use of Two-Photon Lithography with a Negative Resist and Processing to Realise Cylindrical Magnetic Nanowires Askey, Joseph Hunt, Matthew Oliver Langbein, Wolfgang Ladak, Sam Nanomaterials (Basel) Article Cylindrical magnetic nanowires have been shown to exhibit a vast array of fascinating spin textures, including chiral domains, skyrmion tubes, and topologically protected domain walls that harbor Bloch points. Here, we present a novel methodology that utilizes two-photon lithography in order to realize tailored three-dimensional (3D) porous templates upon prefabricated electrodes. Electrochemical deposition is used to fill these porous templates, and reactive ion etching is used to free the encased magnetic nanowires. The nanowires are found to have a diameter of 420 nm, length of 2.82 μm, and surface roughness of 7.6 nm. Magnetic force microscopy in an externally applied field suggests a complex spiraling magnetization state, which demagnetizes via the production of vortices of alternating chirality. Detailed micro-magnetic simulations confirm such a state and a qualitative agreement is found with respect to the switching of experimental nanowires. Surprisingly, simulations also indicate the presence of a Bloch point as a metastable state during the switching process. Our work provides a new means to realize 3D magnetic nanowires of controlled geometry and calculations suggest a further reduction in diameter to sub-200 nm will be possible, providing access to a regime of ultrafast domain wall motion. MDPI 2020-02-28 /pmc/articles/PMC7152837/ /pubmed/32121262 http://dx.doi.org/10.3390/nano10030429 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Askey, Joseph Hunt, Matthew Oliver Langbein, Wolfgang Ladak, Sam Use of Two-Photon Lithography with a Negative Resist and Processing to Realise Cylindrical Magnetic Nanowires |
title | Use of Two-Photon Lithography with a Negative Resist and Processing to Realise Cylindrical Magnetic Nanowires |
title_full | Use of Two-Photon Lithography with a Negative Resist and Processing to Realise Cylindrical Magnetic Nanowires |
title_fullStr | Use of Two-Photon Lithography with a Negative Resist and Processing to Realise Cylindrical Magnetic Nanowires |
title_full_unstemmed | Use of Two-Photon Lithography with a Negative Resist and Processing to Realise Cylindrical Magnetic Nanowires |
title_short | Use of Two-Photon Lithography with a Negative Resist and Processing to Realise Cylindrical Magnetic Nanowires |
title_sort | use of two-photon lithography with a negative resist and processing to realise cylindrical magnetic nanowires |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7152837/ https://www.ncbi.nlm.nih.gov/pubmed/32121262 http://dx.doi.org/10.3390/nano10030429 |
work_keys_str_mv | AT askeyjoseph useoftwophotonlithographywithanegativeresistandprocessingtorealisecylindricalmagneticnanowires AT huntmatthewoliver useoftwophotonlithographywithanegativeresistandprocessingtorealisecylindricalmagneticnanowires AT langbeinwolfgang useoftwophotonlithographywithanegativeresistandprocessingtorealisecylindricalmagneticnanowires AT ladaksam useoftwophotonlithographywithanegativeresistandprocessingtorealisecylindricalmagneticnanowires |