Influences of sintering atmosphere on the magnetic and electrical properties of barium hexaferrites

Abstract

BaFe12O19 (BaM) hexaferrite has drawn increasing attention due to the high magneto-crystalline anisotropy and chemical stability, being a promising candidate in the field of magnetic microwave devices and magnetoelectric multiferroics. In this work, we studied the differences in microstructure and physical properties of BaM ceramics sintered in different atmospheres of nitrogen and air. It is found that N2 atmosphere does not significantly affect the morphology and magnetic properties of BaM, but dramatically reduces the resistivity from ∼ 1010 to ∼ 105 Ω·cm. By virtue of X-ray photoelectron and impedance analysis, the reduced resistance and increased permittivity value of the N2-sintered BaM were ascribed to the electron hopping mechanism caused by the formation of Fe2+ from Fe3+ ions.