Surface Defects: Their Role in Atom Transport and Surface Phase Transitions

这项工作的目的是表征晶体表面的结构缺陷，并研究它们在原子输运过程中的作用。原子在表面上运动以产生形貌变化和表面相变的机制将被研究。这项工作的主要部分将涉及研究单晶表面上的原子步骤；它将涉及台阶附近的原子结构，沿单个台阶的扭结分布，台阶对和台阶群的相互作用，质量传递过程中台阶运动的动力学以及相变成核位置与台阶边缘的相关性。结构和动力学研究的主要实验方法将是扫描隧道显微镜、低能电子衍射和表面x射线衍射。实验将在半导体和金属单晶上进行。

The work is aimed at characterizing structural defects on crystal surfaces and investigating their role in atom transport processes. The mechanisms by which atoms move on surfaces to produce morphology changes and surface phase transitions will be studied. A major part of the work will involve the study of atomic steps on single crystal surfaces; it will be concerned with atomic structure in the vicinity of steps, kink distributions along individual steps, interactions of pairs and groups of steps, the dynamics of step motion during mass transport processes and the correlation of nucleation sites for phase transitions with step edges. The major experimental methods for the structural and kinetic studies will be scanning tunneling microscopy, low energy electron diffraction, and surface x-ray diffraction. Experiments will be performed both on semiconductors and on metal single crystals.