Preparation and Microwave Absorbing Properties of Cu-doped Ni-Zn Spinel Ferrites

摘要

Ni-Zn spinel ferrite and Cu-doped spinel ferrite were prepared by a conventional ceramic processing method.Microwave absorption,complex permittivity and permeability of the (Ni0.5Zn0.5)Fe2O4 and (Ni0.4Cu0.2Zn0.4)Fe2O4 spinel ferrites within the frequency range of 0.5-18 GHz were investigated.The reflection loss calculation results show that the Ni-Zn spinel ferrite and Cu-doped Ni-Zn spinel ferrite are good electromagnetic wave absorbers in the microwave range.The single layer (Ni0.4Cu0.2Zn0.4)Fe2O4 spinel ferrite absorber with a thickness of 9.2 mm achieved a reflection loss below -10 dB (90％ absorption) at 0.5-2.3 GHz,and the minimum value is-35.63 dB at 1.1 GHz.When the first layer and second layer are (Ni0.5Zn0.5)Fe2O4 and (Ni0.4Cu0.2Zn0.4)Fe2O4 spinel ferrites respectively,the laminated absorbers with double spinel ferrite layers with a thickness of 3 mm achieved a reflection loss below-10 dB at 9.9-12.3 GHz,and the minimum value is-35.3 dB at 11.7 GHz.