Preparation and properties of Ba3−xBixCo2+xFe24−xO41 Z-type hexaferrites

Abstract

Abstract In the present work, the effects of Bi/Co co-doping upon the phase constituents, microstructure, magnetic and dielectric properties in Ba3−xBixCo2+xFe24−xO41 (x = 0.05, 0.1, 0.15, 0.2, 0.4) Z-type hexaferrite samples have been investigated. The Ba3−xBixCo2+xFe24−xO41 samples were synthesized by the conventional ceramic methods. The XRD data indicate that the sintered sample with x = 0.05 crystallizes a Z-type hexaferrite main phase with small amount of M-type and Y-type secondary phases. The sample with x = 0.1 have a Z-type hexaferrite structure, while small amount of secondary phases of W-type and Y-type hexaferrites are detected for high Bi/Co co-substitution content (x ≥ 0.15). Bi/Co co-substitution effectively improves the density of the samples, and enhances their magnetic and dielectric properties, especially the high frequency characteristics. The best combination of magnetic and dielectric characteristics is achieved at x = 0.2, with the magnetic permeability of (9.72 ± 0.32) and the cutoff frequency of (2.04 ± 0.13) GHz.