Effect of Zn2+ ion substitution in Al3+-substituted rare-earth free Sr-hexaferrite for different permanent magnet applications

Abstract

Strontium hexaferrites possess magnetic tunability. Most commonly, they are modified with different synthesis processes and the substitution of different elements at Fe or Sr lattice sites. A composition of sol-gel auto-combustion synthesized SrFe8-xAl4ZnxO19 (0 ≤ x ≤ 1) hexaferrites is studied in the present work with the objective of improving the magnetic parameters of strontium hexaferrite magnets. The effect of Zn substitution in the SrFe8Al4O19 hexaferrite is studied on the structural, magnetic, dielectric, and electrical properties. The energy density (BH)max is effectively improved to 19.15 MGOe, which makes this low-cost magnet beneficial in different permanent magnet applications. The dielectric properties have revealed the typical behavior of hexaferrites. It is explained according to the Maxwell-Wagner theory and the Koop model. This work is expected to propose an economical and effective alternative to rare-earth-based permanent magnets. © 2023 Elsevier B.V.