Preparation of Fe20Ni80 submicron fibers by an oxalate precipitation-thermal decomposition process and their microwave absorbing properties

Fe20Ni80 submicron fibers were prepared by an oxalate precipitation-thermal decomposition process, and their morphologies, structures and microwave absorbing properties were systematically investigated. Firstly, an oxalate precursor with a one-dimensional growth mechanism was synthesized by using ethylenediamine as a coordination agent. Secondly, the Fe20Ni80 submicron fibers with a diameter of about 300 nm were obtained by a thermal decomposition of the precursors. The electromagnetic parameters of Fe20Ni80 submicron fibers (20 wt%)/paraffin composite were measured and the microwave absorbing properties were determined by the reflection loss (RL) values in the frequency range of 2-18 GHz. The results show that the composite exhibits excellent microwave absorption properties. When the composite thickness is 2.0 mm, the minimum RL reaches -36.97 dB at 11.89 GHz, and the bandwidth of RL < -10 dB reaches 3.22 GHz (10.36-13.58 GHz).