Investigating the influence of Cr-Zn substitution on magnetic and structural properties of M-type SrBaSm hexaferrites Sr0.6Ba0.1Sm0.3Fe12.0-x(Cr0.6Zn0.4)xO19

The Cr-Zn substituted M-type SrBaSm hexaferrites Sr0.6Ba0.1Sm0.3Fe12.0-x(Cr0.6Zn0.4)xO19 (0.00 ≤ x ≤ 0.75) were synthesized by the conventional ceramic route. The crystal structures were identified by X-ray diffraction. XRD analysis showed that the magnetic powders with CrZn content (x) from 0.00 to 0.30 had M-type as major phase and α-Fe2O3 as impurity phase, while the magnetic powders with CrZn content (x) ≥ 0.45 exhibited a single M-type phase. The grain morphology of the magnets was observed by a field emission scanning electron microscopy (FE-SEM). The FE-SEM images show that all grains were distributed homogeneously and had regular hexagonal platelet-like shape. The magnetic properties of the magnets were derived from the demagnetizing curves. The remanence (Br) and maximum energy product [(BH)max] first increased with increasing CrZn content (x) from 0.00 to 0.30, and then decreased when CrZn content (x) ≥ 0.30. The intrinsic coercivity (Hcj) and magnetic induction coercivity (Hcb) first decreased with increasing CrZn content (x) from 0.00 to 0.30, and then slightly fluctuated and basically remained unchanged when CrZn content (x) ≥ 0.30.