Permeability measurements in cobalt ferrite and carbonyl iron powders and suspensions

摘要: Abstract Magnetic permeability data of cobalt ferrite and carbonyl iron suspensions are discussed. Using an induction method, the relative differential permeability, μr,dif, was measured as a function internal magnetic field for different volume fractions solid phase. In case suspensions, μr,dif−H curve obtained first increasing ramp (data series “1”), decreasing “2”), second one “3”). Series “1” showed maximum in trend that did not appear “2” “3”. Furthermore, “3” always below those “1”. The latter behavior could be ascribed to presence hysteresis, fact it observed where hysteresis is absent. common both types suspensions. It found only disappears if particle motions restricted by dispersing them rigid (epoxy) matrix, or previously structured applying sample prepared elastomer matrix. We conclude maxima curves associated motion orientation dispersed particles during application ramp. comparison with predictions models allows deduce some quantitative information on structures formed particles.