Simple and reproducible preparation of barium hexagonal ferrite by adsorbent combustion method

Barium hexagonal ferrite BaZn2Fe16O27 was rapidly synthesized by adsorbent combustion method. The whole preparation time was controlled within 8 h. The microstructures were studied using powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). The results showed that the pure BaZn2Fe16O27 was obtained after calcined at 1200 degrees C and the particles exhibited homogeneous hexagonal-plate shape with high aspect ratio. Moreover, the complex permeability (mu(r) = mu' - j mu '') and the complex permittivity (epsilon(r) = epsilon' - j epsilon '') were measured in the frequency range of 8-12 GHz (X-band) and 12-18 GHz (K-u-band) using the network analyzer. The as-prepared ferrite exhibited strong magnetic loss properties. The microwave absorbing properties of the single BaZn2Fe16O27 ferrite layer with different thicknesses were also analyzed. The results showed that the minimum reflection loss was -15.3 dB and the bandwidth of reflection loss less than -10 dB reached 7.7 GHz with the absorber thickness only 1.7 mm. The adsorbent combustion method is a kind of ideal method to rapidly prepare barium hexagonal ferrite with excellent microwave absorbing properties. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.