Magnetic properties of Cu2+ substituted Co-ferrite

Copper substituted Co-Cu ferrites Co1 - xCuxFe2O4 (0 <= x <= 0.5) have been studied with Mossbauer spectroscopy, x-ray diffraction, and vibrating sample magnetometer (VSM). The Co-Cu ferrite toroidal core samples were sintered at 860-940 degrees C for 2 h and the initial permeability, quality factor, density and shrinkage were also measured. The crystal structure was found to be an inverse cubic spinel with the lattice constant a(0) = 8.390 angstrom and a(0) = 8.386 angstrom for Co-ferrite and Cu2+ substituted Co-ferrite, respectively, by Rietveld profile analysis using the FULLPROF program. Hyperfine field was decreased with increasing Cu2+ concentration. The saturation magnetization (Ms) of the Co-Cu ferrite annealed at 900 degrees C decreased drastically and the coercivity, Plc, dropped dramatically from about 1419 to 455 Oe as copper concentration x decreased from 0.0 to 0.5. This shows that Ms. Hc can be controlled using Cu content, and initial permeability and quality factor Q is nearly constant in Cu2+ substituted Co-ferrite. The toroidal core data showed that the density and shrinkage of Co1 - xCuxFe2O4 (0 <= x <= 0.5) ferrites increased with increasing quantity of Cu ions. (C) 2011 Elsevier B.V. All rights reserved.