Development of high DC-bias Mn–Zn ferrite working at frequency higher than 3 MHz

Modern high-frequency electronic technology demands Mn–Zn soft ferrite for high DC-bias and low power loss applications. In this study, DMR50B ferrite material with a very attractive DC-bias property and with a lower power loss at high frequency up to 3 MHz was developed employing a conventional ceramic powder processing technique based on our previous study of DMR50 material, indicating its magnetic properties can be further improved by microstructure homogeneity. The core loss is around 200 kW/m3 at 3 MHz, 10 mT and 100 °C, and only around 20 kW/m3 at 700 kHz, 30 mT and 100 °C; its cutoff frequency fr is ∼4 MHz and its incremental permeability μΔ remains constant until HDC = 100 A/m. Furthermore, the electromagnetic characteristics and the microstructure of this new DMR50B material are also discussed.