Procesos de magnetización reversible-irreversible y propiedades de remanencia de ferrita de cobalto coprecipitada

Abstract

Cobalt ferrite was obtained by coprecipitation of iron (II) sulphate and cobalt (II) sulphate in acetone medium. Using the moving Preisach model, the reversible (Mrev) and irreversible (Mirr) components of the magnetization were separated. The parameter η given by η = (dM rev/dMirr)Hi and the moving Preisach parameter km, were evaluated according to the relation η = km χrev in order to investigate the behavior of M . It was found that η is not proportional to the reversible susceptibility, therefore km is a function of the internal field. Isothermal remanent magnetization (IRM) and DC demagnetization (DCD) curves were measured. From these data the δm curve and the Henkel plot were obtained showing that all the points remain under the Wohlfath line indicating that the local disorder dominates (demagnetizing-like effect) over the mean-field effect. The switching field distribution curves were obtained by differentiation of the IRM and DCD curves. The peak values of these switching field distributions differ by a factor of 2.7.