TITLE:
Coupling of the Magnetostriction and Hall Effect in the Porous Magnetorheological Composite
AUTHORS:
Stanislaw BEDNAREK
KEYWORDS:
Hall Effect, Magnetostriction, Non-linearity, Hysteresis, Composite, Porous, Elastic, Ferromagnetic
JOURNAL NAME:
Journal of Electromagnetic Analysis and Applications,
Vol.2 No.1,
January
28,
2010
ABSTRACT: The first part of this paper is presents a method for producing the composite which shows ferromagnetic, highly-elastic and electrically-conducting properties. This composite consists of ferromagnetic particles of the size 0.15-0.25 mm made of the chemically pure iron. The mentioned particles were dispersed in the elastic porous silicone the matrix with pores of the size 0.15-0.25 mm. Colloidal graphite particles of the size not exceeding 0.5 µm were added to the matrix to increase electrical conductivity. The production method consist in mixing particles of iron, graphite and sodium chloride with non-polymerized silicone and rinsing salt particles by water after the matrix polymerization. In its second part the paper provides a description of the measurement system for longitudinal magnetostriction and the Hall voltage. The magnetic field with the induction of ± 8 T produced by the Bitter type magnet was applied to the composite samples. The supplying voltage was applied to these samples and the Hall voltage was measured at the electrodes glued to them. The longitudinal magnetostriction was measured by means of the capacitor with a variable capacity placed at the upper surface of these samples. The linear magnetostriction exceeding ± 6 % and the Hall voltage reaching ± 5.5 nV were detected by the conducted measurements. Both the longitudinal magnetostriction and the Hall voltage show nonlinear changes and hysteresis lopes during the magnetic field application and the supplying current flow. The coupling of these changes and other regularities observed in the investigated composites and especially their non-linearity and hysteresis, are discussed in the final part of the paper.