Influence of Rare Earth (Y3+) on Structural, Dielectric and Magnetic Properties of Cobalt ferrite nanoparticles

Abstract

Present work focusses on the fabrication of rare Earth (Y3+) substituted Cobalt ferrite CoFe2−xYxO4 (x = 0.0, 0.1, 0.3, 0.5, 0.7) employing efficient, cost-effective glycine nitrate method. The phase formation was confirmed by means of X-ray diffraction analysis that indicated a formation of an extra orthoferrite phase after an increased Y3+ (x=0.7) concentration. FESEM micrographs demonstrated uniformly homogenous and agglomerated particles with a decrease in average grain size with increasing Y3+ content owing the larger ionic radii of Y3+. All the prepared samples exhibit semiconducting behaviour and is explained using Maxwell- Wagner equation. Complex impedance and complex electric modulus plots were further studied for complete contribution of grains and grain boundary resistances to conduction and resonance frequencies respectively. Magnetic studies by Vibrating Sample Magnetometer (VSM) show that saturation magnetization (Ms) decreases with increase in Y3+ concentration. Y3+ doped cobalt spinel ferrites are found to have dramatic changes in electrical and magnetic properties that find suitability in magneto-recording devices. From the Mössbauer spectra, isomer shift (δ), quadrupole splitting (QS) corresponding to the tetrahedral [A] site and octahedral [B] sites and hyperfine field have been extracted by the standard least square fitting program NORMOS.