Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8156079 | Journal of Magnetism and Magnetic Materials | 2015 | 7 Pages |
Abstract
M-type strontium ferrite substituted by RE (RE=Sm3+, Er3+) were prepared via a sol-gel method. Polypyrrole (PPy)/ferrite nanocomposites (with 20Â wt% ferrite) were prepared by in situ polymerization method in the presence of ammonium persulfate. Effect of the substituted RE ions on structure, magnetic properties and microwave absorption properties were investigated by X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and vector network analyzer. All XRD patterns show the single phase of strontium hexaferrite without other intermediate phases. The crystallite size of synthesized particle is within the range of 22.2-38.1Â nm. The structural in character of the composites were investigated with FT-IR analysis. It shows that the ferrite successfully packed by PPy. TEM photographs show that the particle size had grown up to 50-100Â nm after coating with PPy. In the magnetization for the PPy/SrSm0.3Fe11.7O19 (SrEr0.3Fe11.7O19) composites, the coercivity (Hc) of the composites both increased compared with the undoped composite while the saturation magnetization (Ms) appeared opposite change with different RE ions. Considering the electromagnetic loss and impedance matching comprehensively, the Er-doped ferrite/PPy composite got the better microwave absorption performance with the maximum RL value of â24.01Â dB in 13.8Â GHz at 3.0Â mm. And its width (<â10Â dB) has reached 7.2Â GHz which has covered the whole Ku band.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Juhua Luo, Yang Xu, Hongkai Mao,