Influence of Er3+ substitution on microwave magnetic performance of BaFe12O19

Barium hexaferrites doped with Er3+, Ba1-xErxFe12O19, x = 0.0, 0.01, 0.02, 0.04, 0.06, were prepared by the conventional ceramic technology. The structure and electromagnetic properties of the calcined samples were studied using powder X-ray diffraction (XRD) and network analyzer (Agilent 8722ET). All the XRD patterns showed the single phase of the magnetoplumbite barium ferrite without other intermediate phase when x is below 0.02. The lattice parameters of ferrites doped with Er3+ decreased, indicating that the substitution of Er3+ occurs on Ba2+ basis site and results in a contract of the crystal cell. The microwave electromagnetic properties of the samples have been studied at the frequency range from 2 to 18 GHz. It was shown that epsilon' increased slightly, and the maximum of epsilon" appeared at low frequency position with Er3+ doping. mu" and mu' were improved significantly when x = 0.01, and the maxima are 2 and 1.7, respectively. The reasons were also discussed using electromagnetic theory.