Magnetic and microwave absorption properties of Ni0.6Zn0.4Fe2O4 /SrFe12O19 composites

Abstract

In this work, pure Ni0.6Zn0.4Fe2O4 (NZFO) and Ni0.6Zn0.4Fe2O4/SrFe12O19 (NZFO/SFO) composites have been prepared by solid-state reaction method, their microwave absorbing and magnetic properties have been systematically investigated. The samples were characterized by XRD, FTIR, SEM, SQUID and VNA. The results show that the maximum reflection loss and bandwidth (RL < −10dB) of Ni0.6Zn0.4Fe2O4 ferrite are −36.25 dB and 5.5 GHz, but the bandwidth below −10dB is divided into two parts. In order to obtain a continuous bandwidth below −10dB for Ni0.6Zn0.4Fe2O4 ferrite, strontium ferrite is added to adjust the microwave absorption performance. When the mass ratio of Ni0.6Zn0.4Fe2O4 ferrite and SrFe12O19 ferrite is 1:2 and the thickness is only 1.8 mm, NZFO/SFO composite exhibits excellent microwave absorbing properties. The maximum reflection loss is −25.9 dB, and the absorption bandwidth for RL < −10dB was 6.4 GHz in the frequency range from 11.6 GHz to 18 GHz, covering the entire x-band. The results show that the improvement of the microwave absorption performance of NZFO/SFO composites is related to the parameters such as interface polarization, dipole polarization, natural resonance, eddy current loss, conduction loss and impedance matching. The ideal experimental results show that the NZFO/SFO absorbent has the characteristics of strong absorption, wide bandwidth, and thin layer, and has broad application prospects in civilian and military fields.