Crystal structure and magneto‐dielectric properties of Co‐Zr co‐substituted Co₂Z hexaferrites

Abstract

A series of Ba1.5Sr1.5Co2+xZrxFe24‐2xO41 hexaferrites (x = 0.00, 0.01, 0.03, 0.05, 0.07, and 0.09) were successfully prepared by the conventional solid‐state reaction method. It was found that as the Co2+ and Zr4+ ions entered the hexaferrite structure, the lattice parameters increased, whereas the relative density increased when x = 0.00‐0.03 and then decreased. A suitable amount of substitution increased the DC resistivity, reduced the magnetic and dielectric losses, and made the μ′$\mu ^{\prime}$ and ε′$\varepsilon ^{\prime}$ closer to each other. At x = 0.03, the relative density and DC resistivity of the samples reached their maxim. Besides, both the magnetic and dielectric losses were lowest within the frequency range of 10 MHz‐1 GHz. Meanwhile, the hexaferrite was impedance matched to free space, and the miniaturization factor was about 15. Therefore, this low‐loss ferrite with almost equal permeability and permittivity could be meaningful for antenna miniaturization and high‐frequency applications.