Electromagnetic properties and microwave absorption of W-type hexagonal ferrites doped with La³⁺

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• 作者：Lianwen Deng ; ^a ; ^{dlw626@163.com} ; Li Ding^a ; Kesheng Zhou^a ; Shengxiang Huang^a ; Zhaowen Hu^a ; Bingchu Yang^a
• 关键词：W-type hexaferrite ; La³⁺ doping ; Sol– ; gel method ; Microwave absorption
• 刊名：Journal of Magnetism and Magnetic Materials
• 出版年：2011
• 出版时间：July 2011
• 年：2011
• 卷：323
• 期：14
• 页码：1895-1898
• 全文大小：375 K

文摘

W-type barium hexaferrites with compositions of Ba₁Co_0.9Zn_1.1Fe₁₆O₂₇ and Ba_0.8La_0.2Co_0.9Zn_1.1Fe₁₆O₂₇ were synthesized by the sol–gel method. The electromagnetic properties and microwave absorption behavior of these two ferrites were studied in the 2–18 GHz frequency range. The microstructure and morphology of the ferrites 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. The XRD patterns show that the main phase of the Co₂W ferrite forms without other intermediate phases when calcined at 1200 °C. The SEM images indicate that flake-like hexagonal crystals distribute uniformly in the materials. Both the magnetic and dielectric losses are significantly enhanced by partial substitution of La³⁺ for Ba²⁺ in the W-type barium hexaferrites. The microwave absorption property of the La³⁺ doping W-type hexaferrite sample is enhanced with the bandwidth below −10 dB around 8 GHz and the peak value of reflection loss about −39.6 dB at the layer thickness of 2 mm.