Enhanced grain-boundary diffusion on power loss of low-temperature-fired NiCuZn ferrites for high-frequency power supplies

NiCuZn ferrite ceramics with high permeability, low power loss and excellent thermal stability are vital materials for high-frequency power devices. This paper analyzed grains growth and grain-boundary diffusion of Ni0.2Cu0.2Zn0.6Fe2O4 ferrite ceramics at lower temperatures by adding optimized additives. X-ray diffraction reveals that the samples are pure spinel ferrite phase sintered at low temperatures. SEM images indicate that uniform and compact NiCuZn ferrite ceramics were obtained at 920 degrees C for 4h, which is very advantageous for low-temperature co-fired ceramic (LTCC) technology. In addition, the ferrite ceramics with higher permeability (411 @ 1MHz), lower power loss in high frequency (442kW/m(3) @ 7MHz) and good thermal stability were synthesized by controlling grains growth and grain-boundary diffusion. The results indicate that this ferrite ceramic material is a good candidate for the application of miniaturized power electronics in high frequency.