Effect of a YIG nanoparticle additive on the magnetic properties of MnZn ferrites for MHz frequency applications

Abstract

In this study, MnZn ferrites with added YIG nanoparticles were developed for MHz frequency applications. The effect of the magnetic YIG additive on the power loss, initial permeability, and cutoff frequency of MnZn ferrites was investigated. A small quantity of added YIG effectively reduces the power loss and concurrently increases the initial permeability. Compared to the results for the MnZn ferrite with no added YIG, the optimal MnZn ferrite with 600 ppm added YIG exhibits a reduction in the power loss at 25°C of 56.4% and 36.6% at 1 MHz/50 mT and 3 MHz/10 mT, respectively, and a 13.9% increase in the initial permeability. This sample also exhibits a good stability of the power loss against temperature. The power loss remains below 205 kW/m3 over temperatures ranging from 25 to 140°C. The effect mechanism of YIG addition on the magnetic properties of MnZn ferrites was studied. An analysis based on the equivalent circuit model showed that the reduction in the eddy current loss and power loss mainly results from the increase in the grain boundary resistance caused by the addition of highly resistive YIG.

Effects of Sn substitution on the microstructural and electromagnetic properties of MnZn ferrite for high-frequency applications

“…It must be emphasized that the eddy current loss accounts for a large proportion of the total core losses due to the induced eddy current at high frequency, especially above the megahertz level [19][20][21]. To suppress the eddy current loss, high-resistance grain boundaries are generally constructed in the MnZn ferrite by doping with high-resistance oxides, such as CaO, SiO 2 , ZrO 2 , Ta 2 O 5 , Nb 2 O 5 , HfO 2 , Mo 2 O 3 , YIG nanoparticles, and even nano-sized dielectric materials [22][23][24][25][26][27][28]. However, adding too much non-magnetic oxide may lead to deterioration of the microstructure and the electromagnetic performance [29].…”