Effect of rare-earth ytterbium doping on the microwave absorption performance of nickel-cobalt ferrite.

In order to investigate the effect of different doping proportions of Yb on the structure and microwave absorption properties of ferrite, a sol-gel method was proposed to prepare spinel NiCoYb Fe O. The crystal shape, particle size, elements, microstructure, electromagnetic loss and microwave absorption properties of NiCoYb Fe O were characterized by X-ray diffraction, inductively coupled plasma emission spectrometry, transmission electron microscopy, scanning electron microscopy and vector network analysis. Results show that nickel-cobalt-ytterbium ferrite microwave absorbing materials can be prepared under optimal conditions, with an average particle size of 38.00-45.00 nm. With the increase in the doping amount, the microwave absorption performance first increases and then decreases. When Yb = 0.02, NiCoYbFeO has the best microwave absorption performance, the best reflection loss is -21.04 dB, and the effective microwave absorption bandwidth in the Ku band is 2.55 GHz (15.45-18.00 GHz). The prepared nickel-cobalt-ytterbium ferrite microwave absorbing material has the advantages of less thickness, light weight, strong reflection loss and simple synthesis method. The excellent absorbing properties of NiCoYbFeO are attributed to the interaction between natural resonance and exchange resonance.