Enhanced Microwave Absorbing Properties of La3+ Substituting Barium Hexaferrite

Barium hexagonal ferrites doped with La3+, Ba1-x La (x) CoTiFe10O19 (x = 0.10, 0.15, 0.20), were prepared by sol-gel combustion method. The structure, magnetic properties, and microwave absorption of the samples were investigated. The X-ray diffraction patterns of the doped ferrites confirmed the formation of the M-type barium ferrite, and no other impurities could be found. The electromagnetic parameter spectra showed that The La3+ ions doped in the ferrite improved complex permittivity and permeability so that microwave absorption was enhanced. The minimum reflection loss of -39.15 dB was obtained for sample x = 0.20 with thickness of 2.4 mm, and the maximum bandwidth of RL <-10 dB can reach to 11.5 GHz when the thickness is 2.0 mm.