Polarization Phenomena in Magnetic Liquids
Department of Electric Power Engineering, Faculty of Electrical Engineering and Informatics, Technical University Košice, Slovakia
Keywords: polarization, magnetic liquid, electric and magnetic field, dielectric spectroscopy, thermal ageing, nanoparticle concentration
This review describes the influence of non-ionizing electric field on polarization phenomena observed via charging currents in magnetic liquid. Transformer oil was a supporting fluid colloidal system. Surfactant as a further component of magnetic fluid acted as surface-active substance preventing settlement of nanoparticles. Thermal ageing of samples with different concentrations of magnetite particles (starting from 10 in 20 nm) was carried out. An influence of DC voltage on charging current was observed in the course of time. Thermal ageing and concentration of magnetic nanoparticles in liquids had an influence on charging current shape. The changes are suitable diagnostics parameters for of quality evaluation of magnetic liquid serving as insulation material.
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