Co-precipitation synthesis and microwave absorption properties of CaMnO3 doped by La and Co

In this paper, co-precipitation synthesized CaMnO3 doped by La and Co was reported for the first time as electromagnetic wave absorbing material. Comparative analysis of results shows that doping of La has a greater effect on the complex permittivity than on the complex permeability. The incorporation of the La and Co makes CaMnO3 get a stronger dielectric polarization effect and lower the resonance frequency, which improves the electromagnetic absorbing properties of it. The wave-absorbing property is pretty good when CaMnO3 doped with La and Co, the maximum reflection loss is −25 dB at 11.71 GHz with a thickness of 2 mm. Moreover, the bandwidth with the reflection loss above 10 dB is reached about 3.5 GHz.