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The crystallization of the amorphous Cu60Zr40 alloy has been studied by differential scanning calorimetry (DSC), scanning Auger microprobe (SAM) and transmission electron microscopy (TEM). The DSC trace showed that the sample exhibited a glass transition at 750 K and a strong exothermic effect beginning from 782 K. An enrichment of the element Zr and significant oxygen contamination in a zone near the surface to a depth of about 10 nm were revealed by SAM in the analysis of surface competition and depth profiles of the Cu60Zr40 sample. Also, the change of concentration ratio of Ca to Zr in amorphous matrix at the clean Cu60Zr40 surface as a function of annealing temperature was examined in detail, and it was found that the concentration of Zr at the surface is slightly higher than that in the bulk until 780K and that the concentration ratio of Cu to Zr in matrix has an abrupt increase in the temperature range of 780-800K. The observations by high resolution TEM revealed the appearance of cluster-like regions of approximately 1.5-2.0 nm in size just before crystallization and they distributed randomly throughout the sample. This phenomenon is analogous to the results obtained using field ion microscopy (FIM) by the present authors. The microstructural changes of the sample daring heating show the gradual crystallization of the amorphous matrix. 相似文献
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场离子显微镜(FieldionMicroscope)是由美国宾夕法尼亚国立大学已故的E.W.Muller教授在1951年发明的一种具有高放大倍数、高分辨率的,并能直接观察表面原子的研究装置.早在1937年,Muller曾发明了场发射显微镜.他在一个金属针尖上加了负的高电压之后,观察到在尖端产生冷电子发射.将其表面状况扩大并投影到荧光屏上,但是这种因隧道效应而产生的冷电子发射,由于发射电子具有?... 相似文献
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薛其坤 厉建龙孙牧 陆华T. Hashizume Y. Ling Y. Hasegawa K. Ohno Z.Q. Li Y. Kawazoe T. Sakurai H. Kamiyama H. Shinohara 《中国科学A辑》2000,30(6):529-536
利用扫描隧道显微镜观测到生长在GaAs(0 0 1 ) 2× 4表面上的固态vanderWaals C60 膜在室温下较之C60 晶体具有 1 3%的晶格膨胀 .这种膨胀是由从GaAs衬底饱和的As悬挂键上转移到C60分子上的电荷之间的Coulomb作用引起的 .理论计算表明 ,平均约有 1 76个电子转移到每个C60分子上 .有趣的是 ,该固态C60 膜为 (1 1 0 )取向 ,这明显不同于生长于其他半导体或金属表面上的具有 (1 1 1 )取向的六角密排C60膜 .这种反常取向的薄膜是由GaAs衬底的各向异性产生的一维限制作用导致的 .通过选择不同的衬底 ,可以控制C60薄膜的晶体生长 相似文献
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Chemisorption of atomic hydrogen on the Si(100)2×1 surface has been investigated in detail by using a field ion-scanning tunneling microscope (FI-STM). The results showed that the adsorption geometry changed from the 2×1 monohydride phase to the 1×1 dihydride phase with increasing exposure of hydrogen. The data of desorption of the hydrogen-saturated Si surface showed that on annealing at 670K the surface becomes highly disordered: the 1×1 dihydride structure is eliminated and the 2×1 reconstructed monohydride is also hardly to identify. When the temperature rises to as high as 730 K, the surface is domi-nated by the 2×1 structure with missing dimer rows, and some adatom chains occur on the Si substrate ler-races. We attribute the formation of these atomic chains to an epitaxial growth of Si atoms which are formed by the dissociation of SiHx (x= 1, 2, 3 or 4) compounds on the Si surface. 相似文献
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The crystallization of the amorphous Cu60Zr40 alloy has been studied by differential scanning calorimetry (DSC), scanning Auger microprobe (SAM) and transmission electron microscopy (TEM). The DSC trace showed that the sample exhibited a glass transition at 750 K and a strong exothermic effect beginning from 782 K. An enrichment of the element Zr and significant oxygen contamination in a zone near the surface to a depth of about 10 nm were revealed by SAM in the analysis of surface competition and depth profiles of the Cu60Zr40 sample. Also, the change of concentration ratio of Ca to Zr in amorphous matrix at the clean Cu60Zr40 surface as a function of annealing temperature was examined in detail, and it was found that the concentration of Zr at the surface is slightly higher than that in the bulk until 780K and that the concentration ratio of Cu to Zr in matrix has an abrupt increase in the temperature range of 780-800K. The observations by high resolution TEM revealed the appearance of cluster-like regions of approximately 1.5-2.0 nm in size just before crystallization and they distributed randomly throughout the sample. This phenomenon is analogous to the results obtained using field ion microscopy (FIM) by the present authors. The microstructural changes of the sample daring heating show the gradual crystallization of the amorphous matrix. 相似文献
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采用新型固态热调制技术的全二维气相色谱-质谱联用法对某工业废水进行分析,定性检出162种主要的有机污染物。结果表明,有机污染物主要由苯系物和萘系物组成;同类化合物在全二维气相色谱谱图上呈规律性排布,可以方便地对性质相近的化合物进行归类分析;全二维气相色谱-质谱法具有更大的峰容量、更高的分辨率和灵敏度,是复杂样品的准确可靠的分析方法。 相似文献
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一、概述东北大学金属材料研究所始建于1916年4月。当时称为东北帝国理科大学临时理化研究所第二部,它是日本的大学附属研究所中历史最长的一个。当时的日本,由于日俄战争(1904年)和第一次世界大战(1914年),迫切需要钢铁自给,因此在由本多光太郎博士担任该所首任所长时,就开始了关于铁的强度等结构?... 相似文献