This title appears in the Scientific Report :
2015
Please use the identifier:
http://dx.doi.org/10.1063/1.4929342 in citations.
Please use the identifier: http://hdl.handle.net/2128/17308 in citations.
Direct observation of electric field induced pattern formation and particle aggregation in ferrofluids
Direct observation of electric field induced pattern formation and particle aggregation in ferrofluids
Ferrofluids typically respond to magnetic fields and can be manipulated by external magnetic fields. Here, we report on formation of visually observable patterns in a diluted low-polarity ferrofluid exposed to external electric fields. This presents a specific type of ferrofluid structure driven by...
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Personal Name(s): | Rajnak, Michal (Corresponding author) |
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Petrenko, Viktor I. / Avdeev, Mikhail V. / Ivankov, Olexandr I. / Feoktystov, Artem / Dolnik, Bystrik / Kurimsky, Juraj / Kopcansky, Peter / Timko, Milan | |
Contributing Institute: |
Streumethoden; JCNS-2 JCNS-FRM-II; JCNS-FRM-II |
Published in: | Applied physics letters, 107 (2015) 7, S. 073108 - |
Imprint: |
Melville, NY
American Inst. of Physics
2015
|
DOI: |
10.1063/1.4929342 |
Document Type: |
Journal Article |
Research Program: |
Jülich Centre for Neutron Research (JCNS) FRM II / MLZ |
Subject (ZB): | |
Link: |
Restricted Restricted OpenAccess OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/17308 in citations.
Ferrofluids typically respond to magnetic fields and can be manipulated by external magnetic fields. Here, we report on formation of visually observable patterns in a diluted low-polarity ferrofluid exposed to external electric fields. This presents a specific type of ferrofluid structure driven by a combined effect of electrohydrodynamics and electrical body forces. The free charge and permittivity variation are considered to play a key role in the observed phenomenon. The corresponding changes in the ferrofluid structure have been found at nanoscale as well. By small-angle neutron scattering (SANS), we show that the magnetic nanoparticles aggregate in direct current (dc) electric field with a strong dependence on the field intensity. The anisotropic aggregates preferably orient in the direction of the applied electric field. Conducting SANS experiments with alternating current (ac) electric fields of various frequencies, we found a critical frequency triggering the aggregation process. Our experimental study could open future applications of ferrofluids based on insulating liquids. |