Role of copper on structural, magnetic and dielectric properties of nickel ferrite nano particles

Copper doped nickel ferrites Ni(1-x)CuxFe2O4 (where x=0.2, 0.4, 0.6) nanoparticles are prepared by coprecipitation method and sintered at 600 degrees C. The XRD study confirms the formation of single-phase cubic spinet Ni-Cu ferrites. The particle size increases with Cu substitution. FT-IR spectra confirm the absorption bands around 554-547 cm(-1) for the tetrahedral sites and around 448-450 cm(-1) for the octahedral sites. The inclusion of copper shifts the tetrahedral band to lower values. The saturation magnetization (M-s) and remanent magnetization (M-r) decrease with increase in copper concentration and the coercivity (H-c) is found to increase for all the compositions sintered at 600 degrees C. The dielectric constant decreases drastically for all the compositions and reaches a constant value. These nanoparticles can be tested for humidity sensing applications. (C) 2015 Elsevier B.V. All rights reserved