Atomic structure of thin dysprosium-silicide layers on Si(111)

We report on scanning tunneling microscopy results of thin dysprosium-silicide layers formed on Si(111). In the submonolayer regime, both a 2 root 3 x 2 root 3 R30 degrees and a 5 x 2 superstructure were found. Based on images taken at different tunneling conditions, a structure model could be developed for the 2 root 3 x 2 root 3 R30 degrees superstructure. For one monolayer, a I x I superstructure based on hexagonal DySi2 was observed, while several monolayers thick films are characterized by a root 3 x root 3 R30 degrees superstructure from Dy3Si5. (c) 2005 Elsevier B.V. All rights reserved.