Pr-Co substituted M-type strontium hexaferrites with the chemical composition of Sr1-xPrxFe12-yCoyO19 (x = 0.00-0.50; y = 0.00- 0.35) were prepared by the solid-state reaction method. Microstructures of the M-type hexaferrite samples were investigated by the X-ray diffraction (XRD) and a field emission scanning electron microscopy (FE-SEM). The single-phase with hexagonal structure is obtained in the M-type hexaferrites with Pr-Co content (0.00 ≤ x ≤ 0.20, 0.00 ≤ y ≤ 0.14). For the M-type hexaferrites with Pr-Co content (x ≥ 0.20, y ≥ 0.14), impurity phases are observed in the structure. The image of the representative magnet exhibits that the M-type hexagonal structure is formed in the magnet. A permanent magnetic measuring system was used to measure the magnetic properties of the M-type hexaferrite magnets. The remanence (B r), maximum energy product [(BH)max] and H k/H cj ratios increase with the increasing substitution content of Pr (0.00 ≤ x ≤ 0.10) and Co (0.00 ≤ y ≤ 0.07), and then decrease with increasing substitution content of Pr (x ≥ 0.10) and Co (y ≥ 0.07). The intrinsic coercivity (H cj) and magnetic induction coercivity (H cb) decrease with increaing Pr-Co content (0.00 ≤ x ≤ 0.30, 0.00 ≤ y ≤ 0.21), and then increase with increasing substitution content of Pr (x ≥ 0.30) and Co (y ≥ 0.21).

Keywords: M-type hexaferrite, Pr-Co substitution, X-ray diffraction, Magnetic properties