Enhanced electromagnetic properties of low-temperature sintered NiCuZn ferrites by doping with Bi2O3

Abstract

NiCuZn ferrite is a material suitable for low-temperature co-fired ceramic (LTCC) technology due to its high permeability and relatively low sintering temperature. The main research questions regarding NiCuZn ferrites are focused on reducing the sintering temperature of the NiCuZn ferrites to achieve compatibility with the Ag electrodes and improve their electromagnetic properties. In this study, the electromagnetic properties of NiCuZn (Ni0.29Cu0.14Zn0.60Fe1.94O3.94) ferrites were enhanced by doping with Bi2O3, resulting in a reduction of the sintering temperature to 925 °C. The findings show that a suitable concentration of Bi2O3 doping could promote the growth of grains and result in NiCuZn ferrites with denser microstructures sintered at a low temperature. Furthermore, adding 0.30 wt% Bi2O3 to NiCuZn ferrite enhances its electromagnetic properties, such as a high real part of permeability (∼937.6 @ 1 MHz), high saturation magnetization (∼60.353 emu/g), low coercivity (∼0.265 kA/m), and excellent dielectric constant (∼14.71 @ 1 MHz). In addition, the chemically compatible Ag electrodes suggest that the NiCuZn +0.30 wt% Bi2O3 ceramics may be acceptable for LTCC technology.