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低温沉积α-Al2O3薄膜是拓展其实际工程应用的关键。本研究以Al、α-Al2O3和Al + 15wt% α-Al2O3为靶材, 用射频磁控溅射在Si(100)基体上沉积氧化铝薄膜。用掠入射X射线衍射(GIXRD)、透射电子显微镜(TEM)、能谱仪(EDS)对所沉积薄膜的相结构和元素含量进行研究, 用纳米压痕技术测量薄膜硬度。结果表明, 在550 ℃的基体温度下, 反应射频磁控溅射Al+α-Al2O3靶可获得单相α-Al2O3薄膜。靶中的α-Al2O3溅射至基片表面能优先形成α-Al2O3晶核, 在550 ℃及以上的基体温度下可抑制γ相形核, 促进α-Al2O3晶核同质外延生长, 并最终形成单相α-Al2O3薄膜。 相似文献
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采用以正硅酸乙酯(TEOS)水解为基础的硅溶胶种子生长法制备了粒径约为270nm的近单分散二氧化硅球型颗粒.采用一种新的溶液生长法,以氢氟酸作为溶液中镍离子配位剂,加入氨水调节溶液pH值的同时作为镍离子补充配位剂,60℃水浴条件下在已制得SiO2微球表面均匀包覆α-Ni(OH)2得到Ni(OH)2/SiO2核壳结构,Ni(OH)2壳层厚度约为35nm.结合多步包覆法提高Ni(OH)2壳层厚度,三次包覆后壳层厚度达到约100nm,四次包覆后约为140nm.采用20wt%的强碱NaOH溶液对三次包覆后的Ni(OH)2/SiO2核壳结构进行处理,得到了壳层厚度约为95nm的α-Ni(OH)2空心微球.空心微球具有较大的比表面积为141.06m2/g. 相似文献
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采用以正硅酸乙酯(TEOS)水解为基础的硅溶胶种子生长法制备了粒径约为270nm的近单分散二氧化硅球型颗粒.采用一种新的溶液生长法,以氢氟酸作为溶液中镍离子配位剂,加入氨水调节溶液pH值的同时作为镍离子补充配位剂,60℃水浴条件下在已制得SiO2微球表面均匀包覆α-Ni(OH)2得到Ni(OH)2/SiO2核壳结构,Ni(OH)2壳层厚度约为35nm.结合多步包覆法提高Ni(OH)2壳层厚度,三次包覆后壳层厚度达到约100nm,四次包覆后约为140nm.采用20wt%的强碱NaOH溶液对三次包覆后的Ni(OH)2/SiO2核壳结构进行处理,得到了壳层厚度约为95nm的α-Ni(OH)2空心微球.空心微球具有较大的比表面积为141.06m2/g. 相似文献
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微波酸消解α-Al2O3研究 总被引:1,自引:0,他引:1
使用MARS-5微波高压消解系统采用HCI或HNO3成功地溶解了α-Al2O3样品,指出当溶剂温度上升至240℃时,HCI或HNO_3对α-Al2O3样品具有较强的溶解能力.当溶剂量固定时,样品量的大小与溶样时间大致成正比关系. Al2O3样品中α相比率越高,消解时间越长. 相似文献
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Thermochemical processing (TCP) with hydrogen, including hydrogenation, intermediate heat treatment and dehydrogenation, of super-2, a type of Ti3Al-based titanium aluminide alloy, was carried out in order to examine the microstructural variations in the alloy. It is shown that a number of microstructural changes, such as the amount, morphology and distribution of different phases in the alloy, can be brought about by TCP. Acicular or Widmanstatten 2 was found to form in the retained B2 matrix under TCP with an intermediate heat treatment of furnace cooling from high temperature, instead of mainly equiaxed 2 under the normal treatment. The precipitation in the microstructures for alloys undergoing TCP with the intermediate -solution heat treatment followed by ageing while dehydrogenating was found to be more regular in morphology and homogeneous in distribution. Both the amount of primary 2 and the size of the primary grains in the microstructure could be controlled by suitable TCP. Some of the reasons leading to the microstructural variations caused by TCP are discussed. 相似文献
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纳米α-Fe2O3制备的研究进展 总被引:1,自引:0,他引:1
综述了近期常用的几种纳米α-Fe2O3制备方法的进展,分类评述了各种方法的优势及存在的问题,指出了发展可控产物粒径和形貌的新途径,揭示了反应的实质,便于其指导并实现大规模工业生产。 相似文献
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爆轰法制备纳米α-Al2O3 总被引:4,自引:0,他引:4
纳米粉体材料是上世纪80年代中期以后发展起来的一种新型固体材料,它由尺寸在(1-100)mm的固体颗料组成.由于纳米材料具有良好的表面效应、体积效应、量子尺寸效应和宏观量子隧道效应,在材料、机械、化工、医药、军事等领域都有广泛的用途. 相似文献
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A simple, versatile route for the synthesis of carbon nanotube supported SnO2 nanoparticles was set up via wet chemical process. Amorphous carbon nanotube (α-CNTs) was used to immobilize SnO2 nanoparticles. α-CNTs was first modified with hydrophilic groups, and then Large density of SnO2 nanoparticles were uniformly decorated into the wall of α-CNTs. The diameters of SnO2 nanoparticles in the wall range from 10 nm to 30 nm, with mean diameters about 22 nm. This approach provides an efficient method to attach other metal oxides and other nanoparticles to carbon nanotubes. 相似文献
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研究了温度对α-Al2O3 -H2O-聚丙烯酸悬浮液分散稳定性的影响.研究表明:温度升高,粉体充分分散时所需的PAA添加量增大.浆料体系中分散剂添加量低于给定温度下的最佳添加量时,温度升高,浆料粘度增加,稳定性下降.但在适量聚丙烯酸(polyacrylic acid,PAA)分散剂存在的前提下,提高温度,可以显著降低高固含量浆料的粘度. 相似文献
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J. Certo C. S. Furtado A. R. Ferreira J. M. Perdigão 《Journal of Materials Science》1995,30(12):3248-3250
The densification of ceramics of -Fe2O3 depends on the processing parameters. The separate influences of milling, sieving, isostatic pressure and sintering atmosphere were investigated. The maximum density, with a value around 96%, was obtained in a sintering atmosphere of nitrogen. 相似文献
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