Microwave absorbing properties of Y2Fe16Si micropowders with broad bandwidth and strong absorption

Abstract

The rare earth-Fe intermetallic compounds with planar magnetocrystalline anisotropy were deemed as hopeful candidates for microwave absorption owing to their higher Snoek’s limit as compared to the cubic spinel-type ferrites. In this work, The Y2Fe16Si alloy was massively produced through strip casting technique, and the microwave absorbing properties of Y2Fe16Si-paraffin composites were studied. The Y2Fe16Si alloy exhibits a single phase of hexagonal Th2Ni17-type structure with a planar magnetocrystalline anisotropy and has a saturation magnetization of 121 emu g−1. It was found that electromagnetic dissipation contributes to microwave absorption but is not the determinative factor in Y2Fe16Si-paraffin composites. Controlling the values of the complex permittivity and the complex permeability in a reasonable range can lead to proper impedance matching. Thus excellent microwave absorbing properties can be obtained. The sample with the mass ratio of 3:1 between Y2Fe16Si and paraffin displays high performance ascribed to its appropriate values of complex permittivity and permeability. A minimum reflection loss (RL) of  −51.6 dB is obtained with a thickness of 1.8 mm. Full covers of the effective bandwidth (RL  <  −10 dB) on the X-band and the Ku-band are achieved when the thicknesses are 1.9 mm and 1.38 mm, respectively. Hence, Y2Fe16Si exhibits excellent potential as a high-performance microwave absorbing material.