Magnetic properties of NiCuZn ferrite nanoparticles synthesized using egg-white

A new process to prepare single-phase nano-sized ferrites, Ni0.80-xCu0.2ZnxFe2O4 with x = 0.1-0.7, was developed using egg-white precursors. TG measurement showed that, the precursors must be calcined at 550 degrees C. XRD patterns indicated the formation of single-phase cubic ferrites with particle size in the range 28.7-48.4 nm. TEM image gave particle size agrees well with that estimated using XRD. FT-IR spectroscopy showed the characteristic ferrite bands. Hysteresis loops measurements exhibited an increase in the saturation magnetization value (M-s) up to zinc content of 0.2 followed by unexpected decrease, which suggests the preference of Zn2+ ions to occupy octahedral sites. The decrease in the coercivity (H-c) with increasing zinc content is attributed to the lower magneto-crystalline anisotropy of Zn2+ ions compared to Ni2+ ions. Temperature dependence of the molar magnetic susceptibility (chi(M)) suggested a ferrimagnetic behavior of the investigated samples and showed a decrease in the value of the Curie temperature (T-C) with increasing zinc. (C) 2010 Elsevier Ltd. All rights reserved.