Effect of cobalt substitution on structural, magnetic and electric properties of nickel ferrite

A series of cobalt-doped nickel ferrite with composition of Ni(1-x)CoxFe2O4 with x ranges from 0.0 to 0.8 (in steps of 0.2) was prepared by using standard ceramic technique. The confirmation of single-phase formation and structural analysis were carried out by employing X-ray diffraction technique. The electrical DC resistivity measurement was done by using usual two probe method in the temperature range from room temperature to 600 degrees C. Room temperature resistivity measurements show the decrease in resistivity with increase of cobalt concentration. The studies on resistivity as a function of temperature shows that all the sample obeys the semiconducting behavior. B-H hysteresis measurement was carried out at room temperature under the field of 2.4 kOe and this measurement with the increase of Co2+ concentration yields the monotonic increase of saturation magnetization (M-s) and decrease in coercive field (H-c) at higher Co2+ concentration (x > 0.4). Ferrites with such behavior are important for magnetic recording media. In view of this, we have studied the various properties of Co-doped Ni ferrite. (C) 2008 Elsevier B.V. All rights reserved.