Electromagnetic wave absorption properties of cobalt-zinc ferrite nanoparticles doped with rare earth elements

Traditional ferrites are of poor electromagnetic wave(EMW) absorption while doping rare earth elements(REEs) can greatly enhance their permeability to improve the EMW loss performance.In this study,Co-Zn ferrite nanoparticles doped with various amounts of REEs(Gd^(3+),Nd^(3+)and Pr^(3+)) were synthesized by a hydrothermal method,and their particle morphology and an EMW absorption performance were characterized by using transmission electron microscopy(TEM) and a Vector network analyzer(VNA).The results show that the initial spherical Co-Zn ferrite nanoparticles present an irregular quadrilateral structure after Gd^(3+)doping,and the average particle size of Co_(0.5)Zn_(0.5-x)Gd_(x)Fe_(2) O_(4) increases from 26 to 50 nm with x increasing from 0 to 0.35.At x of 0.25,the reflectivity absorbance achieves-27.94 dB at 18 GHz with the effective absorption bandwidth(EAB) of 4.08 GHz at a sample thickness of 2.5 mm.When Nd^(3+)doping amount reaches x=0.3,the minimum reflection loss(RL)is-25.63 dB at 18 GHz and EAB is 3.91 GHz.Doping Pr^(3+)(x=0.25) in the sample broadens EAB,and the minimum RL is-16.1 dB at 16.81 GHz and EAB is 7.31 GHz.This study shows that the magnetic moment produced by doping REES can form magnetic domains,which affects the incident EMW and improves the magnetic loss.It is expected that REEs-doped Co-Zn ferrite nanoparticles can be used as efficient electromagnetic shielding materials in aerospace.