Temperature dependent magnetic properties of Co < inf > 1+x < /inf > T < inf > x < /inf > Fe < inf > 2−2x < /inf > O < inf > 4 < /inf > (T = Zr, Ti)

Abstract

This study demonstrates the temperature dependent (carried out at 5, 150 and 300 K) magnetic properties of Zr4+and Ti+4substituted cobalt ferrite samples and their comparison. Polycrystalline Co1+xTxFe2−2xO4(0 ≤ x ≤ 0.4 and T = Zr, Ti) series of compositions were prepared by conventional ceramic method. X-ray diffraction (XRD) confirmed the single phase cubic spinel structure, except for x = 0.4 composition. Coercivity (Hc) is observed to increase substantially with decrease in temperature for all Zr and Ti substituted samples. The magnetization and magnetocrystalline anisotropy constant (K1) were observed to peak at ∼150 K for both the series of samples. Field sensitivity of magnetization (dM/dH) increased with progressive Zr and Ti substitutions. Curie temperature of Co1.2Zr0.2Fe1.6O4and Co1.2Ti0.2Fe1.6O4samples (∼445 °C and 472 °C respectively) decreased compared to that of pure cobalt ferrite (∼517 °C).