Achieving excellent wide-range efficient microwave absorption property by synthesis of Fe-doped CuAlO2 powders via a facile sol–gel route

Abstract

CuAlO2, with a relative higher conductivity than other ceramics, is a potential candidate in microwave absorption fields. Herein, to enhance the wide-range efficient microwave absorption property of CuAlO2 powders, Fe-doped CuAlO2 powders were synthesized via a facile sol–gel method. The X-ray diffraction results displayed that 5 at.% Fe doping CuAlO2 powders maintained the original delafossite structure and excessive Fe doping could destroy the structure of CuAlO2. When the Fe doping content increased to 20 at.%, FeAl2O4 phase formed. The Fe doping had significant effects on the electromagnetic parameters of samples. Compared with pure CuAlO2, the Fe-doped CuAlO2 powders have a higher e″ and µ″, which is beneficial to improve the electromagnetic absorption property. The calculated reflection loss curves demonstrated that the sample with at.% Fe doping displayed the most excellent microwave absorption property in thickness of 3.93 mm, showing a minimum reflection loss of − 20.5 dB at the frequency of 9.86 GHz and reflection loss below − 10 dB in the whole measured frequency. Compared with other potential high temperature microwave absorption materials, Fe-doped CuAlO2 powders exhibit a wide-range microwave absorption property.