Complex permeability and microwave absorption properties of Y _2Fe_(17) micropowders with planar anisotropy

摘要

Planar anisotropy Y_2Fe_(17) powders were fabricated by rapid quenching and ball-milling techniques. The frequency dependence of complex permeability and permittivity of paraffin composites with 35 vol% Y _2Fe_(17) powders have been investigated in the frequency range 0.1-10 GHz. The oriented composite shows a dramatic increase in permeability and a remarkable decrease in the matching thickness. The minimum reflection losses of unoriented Y_2Fe_(17) composite and oriented Y_2Fe_(17) composite were -48 dB at 2.34 GHz and -59 dB at 3.4 GHz, and the corresponding thicknesses were only 3.9 mm and 2.3 mm, respectively. Otherwise, the product of the static permeability and the resonance frequency for the oriented Y_2Fe_(17) compound is 91.6 GHz, which is much higher than the value of 15.3 GHz calculated by Snoek's limit equation. Hence, the Y_2Fe_(17) composite, with the specific property of the planar anisotropy, has great potential applications in the field of high-frequency microwave absorption