Magnetization reversal in co-precipitated cobalt ferrite

A study about the magnetic viscosity and magnetization reversal in co-precipitated cobalt ferrite was carried out. Measurements of direct current demagnetization reversible M-rev and irreversible M-irr magnetization as well as magnetic viscosity S, were performed at room temperature along the demagnetization curve for different applied fields H-ap (0 > H-ap > -7 kOe). From these data M-rev (M-irr)(H) curves were built. The experimental results show a minimum in the M-rev(M-irr)(H), curves and a non-proportionality between S-eta and chi(irr), suggesting two different contributions to the reversal magnetization during the demagnetization process. (C) 2002 Published by Elsevier Science B.V.