Effect of Ag substitution on the electromagnetic property and microwave absorption of LaMnO3

La1−xAgxMnO3 perovskites with different doping Ag-content were prepared by the sol-gel method. The electromagnetic characteristics and microwave loss behavior of these ion-doped rare-earth manganites were studied in the 2-18 GHz frequency range. The microstructure and morphology of the samples were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques. The complex permittivity spectra, the complex permeability spectra and microwave reflection loss were measured by a microwave vector network analyzer system. The XRD patterns show that the crystalline perovskite main phase ABO3 is formed and impurity phases disappear when calcined at 1100 °C, and Ag metal as an impurity phase appears when excessive Ag+ is doped. The SEM image indicates that many of the La0.85Ag0.15MnO3 particles are fiber-like or ellipsoidal. Magnetic loss and dielectric loss coexist and cooperate in microwave attenuation by moderate substitution of Ag+ for La3+. The microwave absorption property of the La0.85Ag0.15MnO3 sample is enhanced with the bandwidth below −10 dB at about 6 GHz and the peak value of reflection loss is near −25.0 dB at the layer thickness of 2 mm.