Thermal evolution of Co on the coexisting Ag/Ge(111)-√3√3 and Ag/Ge(111)-4 × 4 phases

Xiao Lan Huang, Agnieszka Tomaszewska, Chi Hao Chou, Chung Yu Hsu, Chun Liang Lin, Tsu Yi Fu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


Thermal reaction of Co on Ag/Ge(111)- √3 × √3/4 × 4 phases was studied by scanning tunneling microscopy, low energy electron diffraction, and Auger electron spectroscopy. In this paper, we have addressed the controversies over the chemical composition of Co islands by examining the thermal reaction of Co on the coexisting Ag/Ge(111)- √3 × √3 and Ag/Ge(111)-4 9 4 phases. One of the essential findings is that the reaction of Co with the surface proceeds to shift Ag atoms from the beneath of Co-Ge islands into the √3 × √3 unit cell. As a result, a transformation from the 4 9 4 phase into the Agdenser phase occurs on the surface. We also provide the evidence that √13 × √13 periodicity is composed of Co-Ge compound and the 2 9 2 periodicity is composed of pure Co. Ag√3 × √3 prevented the diffusion of Co into substrate at annealing temperature ranging from 320 to 730 K.

Original languageEnglish
Article number1257
JournalJournal of Nanoparticle Research
Issue number11
Publication statusPublished - 2012 Nov


  • Co island
  • Compound
  • Ge(111)
  • Phase transformation

ASJC Scopus subject areas

  • Bioengineering
  • General Chemistry
  • Atomic and Molecular Physics, and Optics
  • Modelling and Simulation
  • General Materials Science
  • Condensed Matter Physics


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