Ultra-low core losses at high frequencies and temperatures in MnZn ferrites with nano-BaTiO3 additives

The miniaturization and integration of power conversion devices and components, such as converters and switching power supplies, require ferrite cores with high operating frequencies and temperatures. Hence, the frequency and temperature dependence of core losses is a bottleneck restricting the development of power conversion devices. Herein, nanoparticles of a dielectric material—barium titanate (BTO)—are adopted to suppress high-frequency and high-temperature core losses in MnZn ferrites. Using a loss separation method, the effects of BTO on core losses and their temperature dependence are investigated. Residual loss at 25 °C and eddy current loss at high temperatures were significantly suppressed by the addition of BTO. Remarkably, adding 0.04 wt% BTO nanoparticles resulted in MnZn ferrites with ultra-low core losses of 302 kW/m3 (25 °C) and 890 kW/m3 (100 °C) at 3 MHz and 30 mT. These superior MnZn ferrites with ultra-low core losses have potential applications in power conversion devices with high operating frequencies and temperatures. This study also provides a novel approach for suppressing core losses.