Microstructure and Magnetic Properties of Low-Fired NiCuZn Ferrite with Different Dopants

The NiCuZn ferrite (Ni_0.60Cu_0.24Zn_0.16Fe₂O₄) has been prepared by a conventional solid-reaction method and sintered at 900°C with different dopants to adapt to the low temperature cofired ceramic (LTCC) technology. Two kinds of dopants, oxide Bi₂O₃ (BI) and ferroelectric ceramic Bi₄Ti₃O₁₂ (BIT), are used in different amounts or combinations (2wt%BI, 2wt%BIT, 2wt%BI + 2wt%BIT, 4wt%BI, and 4wt%BIT) to promote the sintering process. Variation of microstructure and density in each sample has been analyzed. Influence of the doping mode on the magnetic properties of the ferrite has been investigated. It can be found that the ferrite doped with BI has an obvious decrease of both MS and H_C in contrast with the ferrite doped with same amount of BIT. Appropriate amounts of BIT is helpful to not only increase MS, but also decrease of H_C, compared with the ferrite without doping.