I. Introduction
SOFT magnetic powder cores are commonly used in the fields of transformer, generators, and electric machine due to their soft magnetic properties and low total loss [1], [2], [3]. Fe-6.5 wt% Si alloy has been known as a promising candidate for low-to-medium frequency applications because of good saturation magnetization, high electrical resistivity, and near-zero magnetostriction, therefore enhancement of soft magnetic properties and lowering of core loss [1], [4]. As reported by JFE steel [5], the Fe-6.5 wt% Si has become a candidate for application in high-frequency up to 15 kHz.