In this work, the effect of Co substitution in the structural and magnetic properties has been investigated in Ni-Cu-Zn ferrites Ni0.4-xCu0.2Zn0.4CoxFe2O4, Ni0.4Cu0.2Zn0.4-xCoxFe2O4 (x=0, 0.2, 0.4) and Ni0.4Cu0.2-xZn0.4CoxFe2O4 (x=0, 0.1, 0.2). Nanoparticles of ferrites were obtained by hydrothermal method with stirring. A single phase from Ni-Cu-Zn ferrites with cubic spinel structure was formed for all the powders. The lattice parameter has been found to decrease with increasing Co content for all the samples, and this variation in the spinel unit cell is attributed to the difference in the ionic radius of Ni2+, Cu2+, Zn2+ and Co2+ ions. The results show an improvement in magnetic properties by substitution with cobalt, especially for the samples Ni0.4Cu0.2-xZn0.4CoxFe2O4 and Ni0.4-xCu0.2Zn0.4CoxFe2O4 with x=0.2. The saturation magnetization (Ms) of samples increases with the increase of crystallite size after sintering to reach the value of 81.68 Am2 kg-1 . However, the Curie temperature decreased with increasing Co content for the spinel ferrite Ni0.4-xCu0.2Zn0.4CoxFe2O4 and does not change for Ni0.4Cu0.2-xZn0.4CoxFe2O4.
F. Saida, H. Harzali, A. Marzouki, A. Mgaidi, A. Megriche
Spinel Ni-Cu-Zn ferrites, hydrothermal method, cobalt substitution, magnetic properties.