Effects of Nb2O5–WO3 additive on microstructure and magnetic properties of low-temperature-fired NiCuZn ferrites

Abstract

The low-temperature-fired NiCuZn ferrites with different amount of Nb2O5 and WO3 additives were prepared by solid-state reaction method. The effects of Nb2O5 and WO3 additives on sintering behavior, microstructures and magnetic properties of NiCuZn ferrites were investigated. It is found that Nb2O5 and WO3 additives overtly improve the densification of samples through grains uniformity and grains growth promotion. The appropriate Nb2O5 and WO3 additives not only can noticeably increase the initial permeability (μ i ) and saturation flux density (B s ), but also can obviously reduce the remanent flux density (B r ) and coercive field strength (H c ). However, too much additive will deteriorate the magnetic properties. By contrast, 0.2 wt% Nb2O5 and 0.5 wt% WO3 added in NiCuZn ferrites shows excellent magnetic properties: μ i = 674.81 at 100 kHz, B s = 142.48 mT, B r = 63.32 mT and H c = 31.39 A m−1.