The electromagnetic wave absorbing characteristics of MnZn ferrite-TPU composite materials

Abstract

The complex permeability and permittivity (mu(r)*and epsilon(r)*) were investigated for MnZn ferrite-TPU (thermal-plastic polyurethane) composite with ferrite weight percentage varying from 66.7%-88.9%. Fine ferrite powders doped with Mg, Co, and Cu prepared by the citrate gel route were used as fillers. The effective complex permeability and permittivity specta in composites with various ferrite weight percentage were calculated using the Bruggeman effective medium theory. It was found that the dopant content and ferrite/TPU ratio influences the microwave-absorbing characteristics. The results show that the absorbers with (Mg, Co, Cu) doped ferrite have excellent electromagnetic absorption. The reflection loss more than 20dB at the frequencies below 3 GHz can be achieved by controlling the ferrite content and doped elements in the ferrite-TPU composites.