Hexagonal surface structure during the first stages of niobium growth on sapphire (1120)
Hexagonal surface structure during the first stages of niobium growth on sapphire (1120)
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DOI：
10.1080/095008398177823
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发表时间：
1998-11
影响因子：
1.2
通讯作者：
V. Oderno;C. Dufour;K. Dumesnil;A. Mougin;P. Mangin;G. Marchal
中科院分区：
文献类型：
--
作者：
V. Oderno;C. Dufour;K. Dumesnil;A. Mougin;P. Mangin;G. Marchal
在不同的衬底温度下，对铌在（1120）蓝宝石上生长的第一阶段进行了详细的反射高能电子衍射研究。结果表明，当镀层厚度小于某一临界值时，铌薄膜呈现六角形表面结构，该临界值随衬底温度的变化在5 ~ 15 a之间。当厚度大于临界厚度时，表面六边形结构松弛为（110）bcc铌结构。在衬底温度高（820 ~ 410℃）时观察到六角形表面结构，但在衬底温度为270℃时不出现六角形表面结构。给出了衬底、铌表面六边形结构和立方铌相之间的外延关系。
A detailed reflection high-energy electron diffraction study of the first stages of the niobium growth on (1120)s sapphire is presented for several substrate temperatures. It is shown that the niobium film exhibits an hexagonal surface structure when the deposited thickness is smaller than a critical value, which, depending on the substrate temperature, varies between 5 and 15 A. For thicknesses larger than this critical thickness, the surface hexagonal structure relaxes to the (110) bcc niobium structure. The hexagonal surface structure is observed for high substrate temperatures (820-410oC) but does not appear when the substrate temperature is 270oC. The epitaxial relationships between the substrate, the surface hexagonal structure of niobium and the cubic niobium phase are presented.