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 Sr_0.6Ba_0.1Sm_0.3Fe_12.0-x(Cr_0.6Zn_0.4)_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 (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.