...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical review >C_(60) superstructure and carbide formation on the Al-terminated Al_9Co_2(001) surface
【24h】

C_(60) superstructure and carbide formation on the Al-terminated Al_9Co_2(001) surface

机译：C_（60）的上部结构和铝终止的Al_9Co_2（001）表面上的碳化物形成

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We report the formation of an ordered C_(60) monolayer on the Al_9Co_2(001) surface using scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), x-ray and ultraviolet photoelectron spectroscopy (XPS/UPS), and ab initio calculations. Dosing fullerenes at 300 K results in a disordered overlayer. However, the adsorption of C_(60) with the sample held between 573-673 K leads to a [4, -2|1,3] phase. The growth of C_(60) proceeds with the formation of two domains which are mirror symmetric with respect to the [100] direction. Within each domain, the superstructure unit cell contains six molecules and this implies an area per fullerene equal to 91 A~2. The molecules exhibit two types of contrast (bright and dim) which are bias dependent. The adsorption energies and preferred molecular configuration at several possible adsorption sites have been determined theoretically. These calculations lead to a possible scheme describing the configuration of each C_(60) in the observed superstructure. Several defects (vacancies, protrusions,...) and domain boundaries observed in the film are also discussed. If the sample temperature is higher than 693 K when dosing, impinging C_(60) molecules dissociate at the surface, hence leading to the formation of a carbide film as observed by STM and LEED measurements. The formation of Al_4C_3 domains and the molecular dissociation are confirmed by XPS/UPS measurements acquired at different stages of the experiment. The cluster substructure present at the Al_9Co_2(001) surface dictates the carbide domain orientations.
机译：我们报告使用扫描隧道显微镜（STM），低能电子衍射（LEED），X射线和紫外光电子能谱（XPS / UPS）在Al_9Co_2（001）表面形成有序的C_（60）单层。从头算。以300 K的剂量添加富勒烯会导致无序覆盖层。但是，样品C_（60）在573-673 K之间的吸附会导致[4，-2 | 1,3]相。 C_（60）的增长随着相对于[100]方向镜像对称的两个域的形成而进行。在每个结构域中，超结构单元格包含六个分子，这意味着每个富勒烯的面积等于91 A〜2。分子表现出两种类型的对比度（亮和暗），这是与偏压有关的。理论上已经确定了在几个可能的吸附位处的吸附能和优选的分子构型。这些计算导致可能的方案描述了观察到的上部结构中每个C_（60）的构型。还讨论了在膜中观察到的几种缺陷（空位，突起等）和畴边界。如果在加样时样品温度高于693 K，则撞击的C_（60）分子在表面解离，从而导致通过STM和LEED测量观察到碳化物膜的形成。 Al_4C_3结构域的形成和分子解离通过在实验的不同阶段获得的XPS / UPS测量得到证实。 Al_9Co_2（001）表面上存在的簇子结构决定了碳化物畴的取向。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号