Study of Features of the Composition, Magnetic, and Crystal Structure of Barium Hexaferrite BaFe_12 – xTi_xO₁₉

The features of the composition, crystal, and magnetic structure of Ti-substituted barium hexaferrite BaFe_12 – xTi_xO₁₉ (0.25 ≤ x ≤ 1.5) are studied by Mössbauer spectroscopy, vibration magnetometry, X-ray diffraction, and simultaneous thermal analysis. Bounded heterovalent isomorphism implemented by the scheme 2Fe³⁺ → Ti⁴⁺ + Fe²⁺ while retaining the charge balance is established when Fe³⁺ ions are partially substituted with Ti⁴⁺ ions. An increase in the 3d-electron density and the presence of Fe²⁺ in BaFe_12 – xTi_xO₁₉ samples with x = 1.5 is detected by Mössbauer spectroscopy. The heterovalent isomorphic substitution limit is determined to be within 0.75 < x < 1.0. Using Mössbauer spectroscopy and X-ray diffraction, the formation of titanium-contained phases at x = 1.0 whose content increases with the degree of substitution is shown. The data on the preferential distribution of substituent ions (Ti⁴⁺) in the barium hexaferrite structure at the 12k and 2b sites are presented.