The impact of the iron content on the microstructure and magnetic properties of M-type ferrites Sr0.45Ca0.25La0.30FexCo0.25O19

• Sr0.45Ca0.25La0.30FexCo0.25O19 (10.45 ≤ x ≤ 12.25) hexaferrites were prepared by a conventional ceramic method.
• The hexagonal structure is observed for the magnets and the particles are distributed evenly.
• Br, Hcb, Hcj, and (BH)max of the magnets first increase with iron content (x) ranging from 10.45 to 11.05 and then decrease when iron content (x) ≥ 11.05.
• When iron content (x) = 11.05, Br, Hcb, Hcj, and (BH)max of the magnets reach the maximum values.

M-type ferrite Sr0.45Ca0.25La0.30FexCo0.25O19 (10.45 ≤ x ≤ 12.25) magnetic powders and magnets were prepared by a conventional ceramic method. Phase components of the magnetic powders were examined by X-ray diffraction. There is only the magnetoplumbite-type phase in magnetic powders with iron content (x) ranging from 10.45 to 11.65. When iron content (x) ≥ 11.85, hematite (α-Fe2O3) phase begins to occur. The morphology of the magnets was investigated by a field emission scanning electron microscopy. The magnets have formed a hexagonal structure and the particles are distributed evenly. Magnetic properties of the magnets and magnetic powders were measured by a permanent magnetic measuring equipment and a vibrating sample magnetometer, respectively. The remanence, intrinsic coercivity, magnetic induction coercivity, and maximum energy product first increase with iron content (x) of range 10.45–11.05 and then decrease when iron content (x) continues to increase. The magnetic properties at x = 11.05 reach the maximum values.