...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical review >Quantized Electronic Structure And Growth Of Pb Films On Highly Oriented Pyrolytic Graphite
【24h】

Quantized Electronic Structure And Growth Of Pb Films On Highly Oriented Pyrolytic Graphite

机译：高取向热解石墨上铅薄膜的定量电子结构和生长

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 have measured the electronic structure of thin Pb films grown on highly oriented pyrolytic graphite (HOPG) by angle-resolved photoemission spectroscopy. Quantum well states (QWSs) corresponding to confined Pb valence electrons are observed. Their energy positions are fixed, but their intensities evolve for increasing Pb coverages. The results indicate that the films are rough, consisting of multiple thicknesses. Nevertheless, the thickness distribution is sufficiently narrow to allow a unique assignment for each QWS peak in terms of a quantum number and the exact film thickness in atomic layers. For increasing Pb coverages of up to 10 monolayers (ML), the even film thicknesses of 2, 4, 6, 8, and 10 ML are much more prevalent than the odd film thicknesses of 1, 3, 5, 7, and 9 ML, thus suggesting significant differences in surface energy between the even and odd thicknesses. These results are consistent with an available first-principles calculation of the surface energies of freestanding films; an implication is that the interaction between the Pb film and the HOPG substrate is weak. The in-plane dispersion relations of the QWSs are measured. The effective masses at the surface zone center agree well with the results calculated from the bulk Pb band structure, in sharp contrast to the strongly enhanced or anomalous effective masses in Pb films grown on Si(111) as reported previously. This finding indicates that the anomalous effective masses in Pb/Si(111) are not caused by increased electron correlation effects in a confined geometry, but are rather attributable to a strong interfacial interaction between the QWSs and the substrate electronic structure.
机译：我们已经通过角度分辨光发射光谱法测量了在高取向热解石墨（HOPG）上生长的Pb薄膜的电子结构。观察到与受限的Pb价电子对应的量子阱态（QWSs）。它们的能量位置是固定的，但是强度会随着Pb覆盖率的增加而变化。结果表明膜是粗糙的，由多个厚度组成。但是，厚度分布足够窄，可以根据量子数和原子层中的确切膜厚度对每个QWS峰进行唯一分配。为了增加最多10个单层（ML）的Pb覆盖率，偶数膜厚为2、4、6、8和10 ML比奇数膜厚为1、3、5、7和9 ML更普遍。 ，因此表明偶数和奇数厚度之间的表面能有显着差异。这些结果与独立膜的表面能的可用第一性原理计算是一致的。这意味着Pb膜与HOPG基板之间的相互作用较弱。测量了QWS的面内色散关系。表面区域中心的有效质量与从整体Pb带结构计算得出的结果非常吻合，这与先前报道的在Si（111）上生长的Pb薄膜中强烈增强或异常的有效质量形成鲜明对比。该发现表明，Pb / Si（111）中的异常有效质量不是由有限的几何结构中的电子相关效应增加引起的，而是归因于QWS与衬底电子结构之间的强界面相互作用。

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