A new composite material with high saturation magnetization density and high electrical resistivity

Dense composite materials (98.6% of theoretical) consisting of Super Sendust (86.5Fe–6Si–4Al–3.5Ni wt%) and MgFe2O4 (75/25 vol%), which were fabricated by spark plasma sintering for 5 min at 850°C and 130 MPa, exhibit a high saturation magnetization density Bs of 1.2 T and high electrical resistivity ρ of 1 × 10−2 Ω·m. Permeabilities μ >1000 at 1 kHz were obtained. Fine ferrite grains (∼0.6 μm) were located at the boundaries of the large spherical grains of Super Sendust (∼30 μm).