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MgO优异的发射和保护性能会由于水吸附作用形成Mg(OH)2而变差。为了证明这一点,实验首先采用Sol-gel法合成了纯净的MgO粉末:将硝酸镁六水合物和草酸溶解在乙醇中形成凝胶体,接着将该凝胶体在100℃时烘24h以形成草酸镁,然后升温到600℃使之裂解,将其磨碎,再使用240 mesh筛分,最后再在1000℃时烧结2h,形成MgO。该法制成的MgO在气压为10-5mbar的气氛中通过电子束蒸发到玻璃衬底上形成薄膜。以上方法制成的MgO薄膜和在450℃直接退火的MgO薄膜在以下几点做了对比:(a)生长过程和结构;(b)表面形貌;(c)透光度;(d)OH键。以上对比结果表明前者:(i)具有fcc结构,其晶格常数a为4.216±0.005A。,(ii)具有在<100>和<110>之间的择优取向。另外前者还有以下特征:(i)表面形貌呈锥柱状、(ii)可视光范围的高透光度(>88 ~92%)、(iii)无OH键。此外,如果MgO薄膜的晶粒取向{100}和{110}之类的中性面,那么其水合作用就可以得到有效的控制。
The excellent emission and protection properties of MgO deteriorate due to the formation of Mg (OH) 2 due to water adsorption. In order to prove this, the experiment first synthesized the pure MgO powder by Sol-gel method: dissolving magnesium nitrate hexahydrate and oxalic acid in ethanol to form a gel body, and then bake the gel body at 100 ° C. for 24 h to form Magnesium oxalate is then heated to 600 ° C to be cracked, ground, and then sieved with 240 mesh, and finally sintered at 1000 ° C for 2 hours to form MgO. The MgO made by the method is evaporated by electron beam onto a glass substrate under a gas pressure of 10-5 mbar to form a thin film. The MgO films prepared above and the MgO films directly annealed at 450 ° C are compared in the following points: (a) growth process and structure; (b) surface topography; (c) light transmittance; (d) OH key. The above comparison results show that the former: (i) has a fcc structure with a lattice constant a of 4.216 ± 0.005A. , (ii) has a preferred orientation between <100> and <110>. In addition, the former has the following features: (i) pyramidal surface morphology, (ii) high transparency in the visible light range (> 88-92%), and (iii) OH bond free. In addition, the hydration of the MgO film can be effectively controlled if its crystal grains are oriented to the {100} and {110} neutral planes.