Electro-magnetic devices, such as motors and inductors, have been continuously required to increase their operation frequency for high efficiency. To satisfy this requirement, Fe-Si powder cores with high electrical resistance have been attracted much attention although they have lower permeability than Fe-Si electrical steels. With increasing the Si content, the ductility of Fe-Si alloy sharply decreases, which further lowers the density and magnetic properties of cores. In this study, we aimed to fabricate Fe-Si powder cores with higher saturation magnetization and lower loss in 1 ∼ 10 kHz range compared with commercial products. As a result, fabricated Fe-1.5wt% Si@Fe3(PO4)2 cores reached a 98% theoretical density and showed a magnetic flux density of 1.65 T at 10000 A/m and a core loss of 176.8 W/kg at 1 T @ 2 kHz.