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

Abstract

In this paper, co-precipitation synthesized CaMnO 3 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 CaMnO 3 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 CaMnO 3 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.

Rietveld refinement of X-ray powder diffraction data of Ca0.925Ce0.075Mn0.9Fe0.1O3 polycrystalline material

“…Perovoskite manganites possess a strong coupling between electronic and magnetic properties which lead to the exhibition of various properties like metal to insulator transition, colossal magnetoresistance, charge-ordering, ferromagnetic to paramagnetic transition owing to the presence of mixed valence states Mn +4 /Mn +3 (Singh, 2015). Among these perovskite-type oxides, CaMnO 3 is a typical perovskite oxide which shows excellent dielectric polarization behavior, being one kind of dielectric absorbing agent (Zhao et al ., 2015).…”