Magnetic and structural properties of Sr0.75La0.25FexCu0.20O19 (10.40≤x≤11.80) hexagonal ferrites prepared by the solid-state reaction

• The hexaferrite Sr0.75La0.25FexCu0.20O19 (10.40≤x≤11.80) magnetic powders and magnets were synthesized by the solid-state reaction.
• The hexaferrite magnets are formed of hexagonal-shaped crystals.
• At Fe content (x)=11.00, Br and (BH)max for the magnets reach the maximum values. At Fe content (x)=11.20, Hcj and Hcb for the magnets reach the maximum values.

In this study, the hexaferrite magnetic powders and magnets according to the formula Sr0.75La0.25FexCu0.20O19, where x ranging from 10.40 to 11.80 with a step of 0.2 were prepared by the solid-state reaction. X-ray diffraction was performed to investigate the microstructures of the magnetic powders. The results show that a single magnetoplumbite phase is obtained for the magnetic powders with Fe content (10.60≤x≤11.60). For the magnetic powders with Fe content (x) of 10.40 or 11.80, magnetic impurities appear in the structure. A field emission scanning electron microscopy was hired to explore the micrographs of the magnets. The hexaferrite magnets are formed of hexagonal-shaped crystals. A magnetic properties test instrument was used in order to study the magnetic properties of the magnets. The remanence and maximum energy product first increase with Fe content (x) from 10.40 to 11.00 and then begin to decrease when Fe content (x) continues to increase. While the intrinsic coercivity and magnetic induction coercivity first increase with Fe content (x) from 10.40 to 11.20 and then decrease when Fe content (x)>11.20.