Variation of Magnetic Fluid Deformation Related to Nanoparticle Concentration in Steady Electric Field

Abstract

Today, it is important to know the behaviour of magnetic fluids applied in the power electrical machines, e.g. in power transformers, when exposed to an electric field. Besides their promising applications in high voltage engineering, they are of increasing interest from designed assembly and pattern formation point of view. The structure of such magnetic fluids is easily controllable by external magnetic fields. However, less attention has been paid to structural phenomena in magnetic fluids induced by electric fields. The core of this paper is dedicated to the experimental observation of a magnetic fluid droplet deformation in a steady electric field. The mutual relation between the deformation parameter and magnetic nanoparticles concentration is analysed. Spatio-temporal analysis of the droplet shape is presented in the paper. The phenomena of the droplet deformation were recorded by a camera. The detailed experimental procedure is presented. The method of deformation parameter calculation based on the linear pixel as the smallest-size unit in digital image is written. Finally, the relation between the deformation parameter and the nanoparticle volume concentration, as well as the time and magnitude of the DC field application are thoroughly evaluated. The results show that the deformation parameter decreases with increasing concentration at constant applied steady electric field but increases with increasing applied steady electric field.

Spin Relaxation Effects in Oil-Nanomagnetite Ferrofluids - Mössbauer Spectrometry Studies

“…These particles are responsible e.g. for very peculiar spin and dielectric relaxation processes, magnetic mesostructuring, as well as change of magnetic and electro-rheological properties under influence of the external electric field [5][6][7][8][9][10].…”