Fabrication and properties of Z-type Sr3Co2−Zn Fe24O41 hexaferrites and their composites with epoxy

Abstract

Zn-substituted Z-type Sr hexaferrites (Sr3Co2−xZnxFe24O41, x = 0, 0.5, 1.0, 1.5) were prepared by solid-state reaction routes. The magnetic and high-frequency properties of the sintered bodies and powder–epoxy composites were studied. Almost-single-phase Z-type hexaferrite could be obtained in the sample calcined at 1160 °C and then sintered at 1210 °C. Double hysteresis behaviors were observed for the Z-type hexaferrites with x = 1.0 and 0.5. Gradual shifts of the μ' and μ″ spectra to lower frequencies accompanied with gradual increases in their intensities were observed with the increase in the Zn substitution content x, owing to the decrease in the magnetocrystalline anisotropy. Complex permeability and permittivity measurements of the Z-type hexaferrite–epoxy composites were performed using a network analyzer. The composites exhibited magnetodielectric properties with low loss factors (μ″ and ε″ ≈ 0) under 1 GHz and good electromagnetic wave absorption performances up to several gigahertz.