Effect of Y-La-Co substitution on microstructure and magnetic properties of M-type strontium hexagonal ferrites prepared by ceramic method

M-type permanent magnetic ferrites Sr0.95−xY0.05LaxFe11.75Co0.25O19 (x = 0.00, 0.10, 0.20, 0.30, 0.40) have been prepared by ceramic process and investigated systematically. The phase compositions were examined by X-ray diffraction, the results showed that the single phase was obtained when x ≤ 0.30. The morphology of the magnets was investigated by scanning electron microscopy (SEM), the micro-morphology of the particles exhibited the uniform plane hexagonal structure with different lanthanum content. Magnetic properties of the sample were measured by a physical property measurement system-vibrating sample magnetometer (PPMS-VSM). The saturation magnetization (Ms) decreases constantly with the increasing of La content (x). However, the coercivity (Hc) increases as the increasing of doping content.