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)(x)O-19 (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 alpha-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 (B-r) 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 (H-cj) and magnetic induction coercivity (H-cb) 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.