Electrical and magnetic properties of Mg0.85Co0.15Fe2O4 ceramics with V2O5 additives

In this study, magnesium-cobalt ferrite (Mg0.85Co0.15Fe2O4) powder was synthesized using a solid-state synthesis method, followed by the liquid sintering using 0.50-3.00 wt% vanadium oxide (V2O5) at 1050 degrees C for 2 h. X-ray diffraction (XRD) studies confirmed the formation of spinel ferrite. Microstructure studies revealed that by increasing the amount of V2O5 from 0.50 to 3.00 wt%, the average grain size was reduced from 15.9 +/- 5.9 to 7.0 +/- 2.5 mu m and the samples were highly densified. V2O5 promoted the sintering process and reduced the dielectric constant (epsilon '), loss tangent (tan delta), and increased electrical resistivity. A magnesium-cobalt ferrite sample with 25.4 dielectric constant, 0.078 loss tangent, and 9.0 x 10(5) omega.cm resistivity at 1 MHz was achieved using 3.00 wt% V2O5. Increasing V2O5 content caused increasing coercivity (Hc) from 89 to 129 Oe. Moreover, the maximum saturation magnetization (Ms) value of 26.8 emu/g was obtained for the sample containing 1.50 wt% V2O5. The small dielectric loss tangent of the samples at 1 MHz suggests applications of these ceramics in microwave devices.