Dielectric and microwave absorption properties of FeSiAl/Al2O3 composites containing FeSiAl particles of different sizes

Abstract Herein, the effects of FeSiAl particle size on the dielectric and microwave absorption properties of FeSiAl/Al2O3 composites were studied. FeSiAl/Al2O3 composites containing 18-25 μm, 25-48 μm, and 48-75 μm FeSiAl particles were prepared by hot-pressed sintering based on uniformly mixed FeSiAl and Al2O3 powders. Results show that the real permittivity and the imaginary permittivity are significantly promoted with increasing FeSiAl particle size, which is ascribed to the enhanced interfacial polarization and conductance loss. In addition, the favorable matching impedance and suitable attenuation coefficient enabled the composite containing 25-48 μm FeSiAl powder to show a minimum reflection loss of -34.4 dB at 11.7 GHz and an effective absorption bandwidth (