Microwave Absorbing Performance of RE-Fe Based Alloys

RE13Fe84Cr3 (RE=Ce, Pr, Tb, Er) and Pr13-xFe84Cr3Tix(x=0, 2, 4, 6) alloy powders were prepared by arc smelting method and high energy ball milling technique. The phase structure and the morphology of the alloy powders were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and their microwave absorbing properties were determined by a vector network analyzer. The results show that the alloys with light rare earths (Ce, Pr) have good low frequency absorbing property and those with heavy rare earths (Tb, Er) exhibit an improved high frequency absorbing property. The minimum reflectivity at the absorbing peak frequency of RE13Fe84Cr3 (RE=Ce, Pr, Tb, Er) are -9.49 dB at 5.76 GHz, -22.38 dB at 7.92 GHz, -18.52 dB at 11.68 GHz and -17.59 dB at 10.24 GHz, respectively. The absorbing bandwidth under -10 dB of the Pr13Fe84Cr3 powder was widened from 1.91 GHz to 3.89 GHz by adding 2% Ti, but the reflectivity of the alloy was increased from -22.38 dB to -14.91 dB.