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Field-controlled structures in ferromagnetic cholesteric liquid crystals
One of the advantages of anisotropic soft materials is that their structures and, consequently, their properties can be controlled by moderate external fields. Whereas the control of materials with uniform orientational order is straightforward, manipulation of systems with complex orientational ord...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Association for the Advancement of Science
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5630240/ https://www.ncbi.nlm.nih.gov/pubmed/28989965 http://dx.doi.org/10.1126/sciadv.1701336 |
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author | Medle Rupnik, Peter Lisjak, Darja Čopič, Martin Čopar, Simon Mertelj, Alenka |
author_facet | Medle Rupnik, Peter Lisjak, Darja Čopič, Martin Čopar, Simon Mertelj, Alenka |
author_sort | Medle Rupnik, Peter |
collection | PubMed |
description | One of the advantages of anisotropic soft materials is that their structures and, consequently, their properties can be controlled by moderate external fields. Whereas the control of materials with uniform orientational order is straightforward, manipulation of systems with complex orientational order is challenging. We show that a variety of structures of an interesting liquid material, which combine chiral orientational order with ferromagnetic one, can be controlled by a combination of small magnetic and electric fields. In the suspensions of magnetic nanoplatelets in chiral nematic liquid crystals, the platelet’s magnetic moments orient along the orientation of the liquid crystal and, consequently, the material exhibits linear response to small magnetic fields. In the absence of external fields, orientations of the liquid crystal and magnetization have wound structure, which can be either homogeneously helical, disordered, or ordered in complex patterns, depending on the boundary condition at the surfaces and the history of the sample. We demonstrate that by using different combinations of small magnetic and electric fields, it is possible to control reversibly the formation of the structures in a layer of the material. In such a way, different periodic structures can be explored and some of them may be suitable for photonic applications. The material is also a convenient model system to study chiral magnetic structures, because it is a unique liquid analog of a solid helimagnet. |
format | Online Article Text |
id | pubmed-5630240 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | American Association for the Advancement of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-56302402017-10-08 Field-controlled structures in ferromagnetic cholesteric liquid crystals Medle Rupnik, Peter Lisjak, Darja Čopič, Martin Čopar, Simon Mertelj, Alenka Sci Adv Research Articles One of the advantages of anisotropic soft materials is that their structures and, consequently, their properties can be controlled by moderate external fields. Whereas the control of materials with uniform orientational order is straightforward, manipulation of systems with complex orientational order is challenging. We show that a variety of structures of an interesting liquid material, which combine chiral orientational order with ferromagnetic one, can be controlled by a combination of small magnetic and electric fields. In the suspensions of magnetic nanoplatelets in chiral nematic liquid crystals, the platelet’s magnetic moments orient along the orientation of the liquid crystal and, consequently, the material exhibits linear response to small magnetic fields. In the absence of external fields, orientations of the liquid crystal and magnetization have wound structure, which can be either homogeneously helical, disordered, or ordered in complex patterns, depending on the boundary condition at the surfaces and the history of the sample. We demonstrate that by using different combinations of small magnetic and electric fields, it is possible to control reversibly the formation of the structures in a layer of the material. In such a way, different periodic structures can be explored and some of them may be suitable for photonic applications. The material is also a convenient model system to study chiral magnetic structures, because it is a unique liquid analog of a solid helimagnet. American Association for the Advancement of Science 2017-10-06 /pmc/articles/PMC5630240/ /pubmed/28989965 http://dx.doi.org/10.1126/sciadv.1701336 Text en Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). http://creativecommons.org/licenses/by-nc/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license (http://creativecommons.org/licenses/by-nc/4.0/) , which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited. |
spellingShingle | Research Articles Medle Rupnik, Peter Lisjak, Darja Čopič, Martin Čopar, Simon Mertelj, Alenka Field-controlled structures in ferromagnetic cholesteric liquid crystals |
title | Field-controlled structures in ferromagnetic cholesteric liquid crystals |
title_full | Field-controlled structures in ferromagnetic cholesteric liquid crystals |
title_fullStr | Field-controlled structures in ferromagnetic cholesteric liquid crystals |
title_full_unstemmed | Field-controlled structures in ferromagnetic cholesteric liquid crystals |
title_short | Field-controlled structures in ferromagnetic cholesteric liquid crystals |
title_sort | field-controlled structures in ferromagnetic cholesteric liquid crystals |
topic | Research Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5630240/ https://www.ncbi.nlm.nih.gov/pubmed/28989965 http://dx.doi.org/10.1126/sciadv.1701336 |
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