Correlation between the Chemical Composition, Crystal Structure, and Magnetic Properties of Hexagonal Barium Ferrite with Zn2+ Heterovalent Substitution

Abstract

This paper presents a detailed study of the magnetic and crystal structures of BaFe 12 -x Zn x O 19 (0.25 ≤ x ≤ 1.5) Zn-substituted barium hexaferrite by Mössbauer spectroscopy, vibrating sample magnetometry, and X-ray diffraction. Partial heterovalent substitution of Zn 2+ ions for Fe 3+ ions demonstrates limited heterovalent isomorphism according to the scheme 2Fe 3+ → Zn 2+ + Fe 4+ , which satisfies the electroneutrality constraint. Mössbauer spectroscopy results indicate the presence of Fe 4+ in the BaFe 12 -x Zn x O 19 materials. The heterovalent isomorphous substitution limit has been determined to be x = 1.0. The formation of a zinc spinel has been shown to begin at x = 0.50 and its content increases with increasing zinc content. Data are presented on the predominant character of the substituent ion (Zn 2+ ) distribution in the structure of barium hexaferrite. A correlation has been found between the chemical composition, phase separation, anisotropy of properties, and the temperature of the magnetic phase transition of BaFe 12 -x Zn x O 19 (0.25 ≤ x ≤ 1.5).