Magnetic and morphological properties of Ca substituted M-type hexaferrite powders synthesized by the molten salt method

The doping element and morphology are important factors for improving the magnetic properties of M-type hexaferrite powder. As the demand for electromagnetic absorber and magnetic sensors increases in the market, it is required to develop hexaferrite powder with a homogenous shape and excellent magnetic properties. In this study, Ca substituted strontium hexaferrite powders were synthesized by the molten salt method under various calcination conditions. The morphology and magnetic properties of the synthesized powders were successfully controlled according to the Ca content and calcination conditions. As a result, single-crystalline Sr0.90Ca0.10Fe12O19 powders with an average thickness of 0.4 µm were successfully obtained by calcining at 950 °C for 1 h. The synthesized powders had a magnetic saturation of 74.9 emu/g and a coercivity of 3397 Oe.