Extreme Temperature Permeability Engineered Soft Magnetics

Applications may require high temperature power components, either due to temperature rise or high ambient temperatures. For temperatures greater than 300 C and frequencies greater than 1 kHz, novel nanocrystalline soft magnetic materials based upon Co- and FeCo-alloy systems become uniquely relevant due to the limitations of permalloys, ferrites, and amorphous alloys. Controlling material permeability directly (i.e. “permeability engineering”) through advanced manufacturing to produce an induced magnetic anisotropy within the core rather than gapping is also desired to avoid instabilities of binders and resins used in the gapping process. However, the temperature stability of permeability engineered nanocrystalline alloys has not been well explored in the literature. Here we present measurement comparisons of current materials for high temperature and frequency, show impact of high temperature and large excitation on stabilities of anisotropies in relevant materials, and discuss limitations and opportunities for future materials.