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采用水解沉淀法和包裹沉淀法制备不同 Al2 O3/ Si O2 比的纳米粉体 .利用 ICP、XRD、TEM、BET和 IR技术分别检测了粉末的化学组成、晶相、形态、比表面积及红外发射率 .初步讨论了缺位型反尖晶石结构具有高红外发射率的机理 .结果表明 ,具有缺位反尖晶石结构晶相 γ-Al2 O3或 Al-Si尖晶石在 8～ 1 5μm波段具有高的发射率 .另外 ,具有对称性低的片状粒子粉末比球形粒子的粉末具有更高的红外发射特性 ;纳米级粒子粒径减小 ,散射系数减小 ,有利于发射率的提高
The nano-powders with different ratios of Al 2 O 3 / Si 2 O were prepared by hydrolytic precipitation method and precipitation method.The chemical composition, crystal phase, morphology, specific surface area and infrared emission of the powders were measured by ICP, XRD, TEM, BET and IR techniques respectively The mechanism of high IR emissivity of the vacancy-type anti-spinel structure was discussed preliminarily.The results showed that the crystal structure of γ-Al 2 O 3 or Al-Si spinel with vacancies of the inverse spinel structure is in the range of 8 ~ 15μm In addition, the sheet-like particles with low symmetry have higher infrared emission characteristics than those with spherical particles. The reduction of the size of the nanoparticles and the decrease of the scattering coefficient contribute to the improvement of the emissivity