Mean-field model for BaFe[formula omitted]Ti[formula omitted]O19 ([formula omitted] 0 and 0.2) hexaferrite: Structural and magnetic properties.

An experimental and theoretical investigation of the magnetic properties of Ti-doped barium hexaferrite (BaM) is conducted. Polycrystalline samples of BaFe 12 − x Ti x O 19 with x ≤ 0.2 were synthesized using the solid-state reaction method. X-ray diffraction (XRD) analyses, along with Rietveld refinement, confirmed the presence of BaFe 12 O 19 as the predominant BaM phase and a minor amount of hematite in all samples. Structural analysis revealed a slight increase in lattice parameters a and c for x = 0. 2. A result mostly related to the preferential occupation of Ti 4 + ions at the 4f 2 and 12k sites, coupled with the reduction of Fe3＋ ions to Fe2＋. It was also found that the magnetic response of samples is affected by Ti 4 + substitution. Saturation magnetization slightly decreased from ∼ 45 (x = 0) to ∼ 44 emu/g (x = 0.2), the anisotropy constant from ∼ 4. 08 × 105 to ∼ 4. 06 × 105 erg/g 2 , while coercivity slightly increased from ∼ 2456 to ∼ 2468 Oe, and the anisotropy field from ∼ 18.2 to ∼ 18.6 kOe. The magnetic features of the samples were analyzed in terms of a proposed model based on the mean-field theory. Results indicated that the substitution of Ti 4 + ions resulted in a decrease in the magnetic moment of the 2b sublattice. Such behavior is influenced by its closest neighboring sites 12k and 4f 2 sublattices, which are the preferred occupancy sites for the Ti 4 + cations. [ABSTRACT FROM AUTHOR]