Abstract
After deposition of rare-earth elements (Dy, Tb) on Si(111) at elevated temperatures, a formerly unknown reconstruction is observed by low-energy electron diffraction, while scanning tunneling microscopy measurements exhibit a reconstruction. On the basis of density-functional theory calculations, the structure of the larger unit cell is explained by periodically arranged subsurface Si vacancies. The vacancy network in the first subsurface layer has a periodicity, while strain is released by a Si vacancy network in the second subsurface layer. In addition, this vacancy network forms quasi-one-dimensional structures (striped domains) separated by periodically arranged antiphase domain boundaries. The diffraction spot profiles are explained in detail by kinematic diffraction theory calculations, and average domain widths are deduced.
1 More- Received 14 July 2016
- Revised 1 October 2016
DOI:https://doi.org/10.1103/PhysRevB.94.205431
©2016 American Physical Society