Magnetic properties of Ni ferrites substituted by divalent Zn, Cu and Co ions

Substituted Ni ferrite samples with chemical composition Ni 1-x-y-z Zn x Cu y Co z Fe 2 O 4 , where x = 0.4, 0.5 and 0.6, y = 0.1, z = 0.01 and 0.02 were prepared by classical ceramic technology at the temperature of 1200°C. The influence of divalent Zn, Cu and Co ions substitution on the magnetic properties of spinel Ni ferrites was studied. The magnetic properties, such as the Curie temperature, coercive field, remanent magnetic flux density, hysteresis loop area as well as the amplitude and initial permeability were investigated by means of thermo-magnetic analysis and magnetisation curves measurements at low frequencies.