“…Among the permanent magnets ferrites, hard magnetic barium hexaferrite (BaFe 12 O 19 ) has been widely used due to its low cost, excellent oxidation-corrosion resistance, low density, high electrical resistivity, high saturation magnetization and large coercivity [1,2]. It is widely used in many applications, such as recording [3], microwave devices [4] and magnetofluid medicine [5].…”