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

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• 作者：Shengxiang Huang ; Lianwen Deng ; Kesheng Zhou ; Zhaowen Hu ; Shuyuan Sun ; Yuanwei Ma ; Peng Xiao
• 关键词：LaMnO3 perovskite ; Ag+ doping ; Sol&ndash ; gel method ; Microwave absorption
• 刊名：Journal of Magnetism and Magnetic Materials
• 出版年：2012
• 出版时间：September, 2012
• 年：2012
• 卷：324
• 期：19
• 页码：3149-3153
• 全文大小：490 K

文摘

La_1?xAg_xMnO₃ 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 ¡ãC, and Ag metal as an impurity phase appears when excessive Ag⁺ is doped. The SEM image indicates that many of the La_0.85Ag_0.15MnO₃ 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 La_0.85Ag_0.15MnO₃ 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.