マグネタイトとケイ酸カルシウムの同時水熱合成による電波吸収体の作成 Electromagnetic Wave Absorber Composed of Magnetite and Calcium-silicate Obtained by Simultaneous Hydrothermal Synthesis
The simultaneous hydrothermal synthesis is described on spinel-type ferrites from ferrous hydroxide with 0.34mol% Ni(OH)<sub>2</sub> and matrix materials in CaO-SiO<sub>2</sub> system. It is possible to synthesize large-size particles of ferrous hydroxide by the presence of NH<sub>4</sub>Cl as a reactive moderator, while the presence of Ni<sup>2+</sup> promotes magnetite synthesis in the simultaneous hydrothermal synthesis method. The simultaneous synthesis composite has a Fe content of 60wt% in the form of Fe<sub>3</sub>O<sub>4</sub>, with matching characteristics of -40dB for reflection loss and 4.0 mm thickness at 5.77GHz for the single-layer electromagnetic wave absorber. In the case of a double-layer type electromagnetic wave absorber for ETC systems, in 5.8GHz, the first layer is a calc-silicate plate of 7.3mm thickness, with the second layer being a 7.9mm thick simultaneous synthetic composite of 80wt% Fe (as Fe<sub>3</sub>O<sub>4</sub>). The double-layer type electromagnetic wave absorber has the same absorbing properties as the composite obtained from commercial Mn-Zn ferrite and matrix materials in CaO-SiO<sub>2</sub> system.<BR>The new method for synthesis of electromagnetic wave absorber, described in this study, can be readily achieved for practical utilization, and expected to provide simple and efficient manufacturing of electromagnetic wave absorber at low cost.
- 資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan
資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan 120(2), 126-130, 2004-02-25