Characterization of Ni–Cu–Zn ferrite prepared from industrial wastes

We propose the distillation method to synthesize Ni–Cu–Zn ferrite powder and to recover nitric acid, using scrap iron and the waste solution of electroplating as the starting materials. It was found that the Ni–Cu–Zn ferrite powder prepared from industry wastes also showed the formation of cubic ferrite with a saturation magnetization (Ms) of 55,825 A m2 g−1 and an intrinsic coercive force (Hci) of 579 A m−1. For sintered Ni–Cu–Zn ferrite specimen, the toroidal specimen sintered at 950 °C for 2 h presented an maximum initial permeability (μi) of 176 at 28.3 MHz, a maximum quality factor (Q) of 32 at 3 MHz. The AC impedance measurements were performed by using impedance analyzer Solartron 1260. The semicircles in the impedance spectra shift to higher frequencies with increasing temperatures. The values of resistance (grain interior, grain boundary, and total) decreased with increasing temperatures. The semicircles of grain boundary and electrode are observed clearly. These data can be used to analyze typical the grain interior and the grain boundary resistance of Ni–Cu–Zn ferrite.