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Title: Anomalous structural evolution and √(3)×√(3) reconstruction of a clean Si(111) surface observed after thermal desorption of thallium

The authors have observed anomalous structural evolution of a clean Si(111) surface, which was prepared first by thallium (Tl) deposition on a Si(111)7 × 7 surface, leading to incomplete formation of a Tl/Si(111)1 × 1 structure at 300 °C and subsequent desorption of Tl at 350 °C. Thus prepared clean Si(111) surfaces exhibit structural changes with increase of temperature: 2×1→(√(3)×√(3))R30°→2×1→5×5→7×7, as observed by low-energy electron diffraction and scanning tunneling microscopy. Among the above structures, the (√(3)×√(3))R30° formed at 450–550 °C is found not to be a simple adatom structure. Instead, by means of ab-initio calculations a new metastable (√(3)×√(3))R30° reconstruction was found, having analogous structural features and formation origin to a 2 × 1 reconstruction known as the Pandey chain model. This new (√(3)×√(3))R30° model is 0.09 eV per surface atom less favorable than the 2 × 1 reconstruction. A reason for the anomalous occurrence of the (√(3)×√(3))R30° structure is explored with an aid of Monte Carlo simulations.
Authors:
 [1] ;  [2] ;  [3]
  1. Charles University in Prague, Faculty of Mathematics and Physics, V Holešovičkách 2, 180 00 Prague 8 (Czech Republic)
  2. Charles University in Prague, Faculty of Mathematics and Physics, V Holešovičkách 2, 180 00 Prague 8, Czech Republic and Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, CZ-162 00 Prague (Czech Republic)
  3. Department of Molecular and Material Sciences, Kyushu University, Kasuga, Fukuoka 816-8580, Japan and Department of Electronics Engineering and Computer Science, Fukuoka University, Fukuoka 814-0180 (Japan)
Publication Date:
OSTI Identifier:
22392151
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; Journal Volume: 33; Journal Issue: 2; Other Information: (c) 2015 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; ATOMS; COMPUTERIZED SIMULATION; DEPOSITION; DESORPTION; ELECTRON DIFFRACTION; MONTE CARLO METHOD; SCANNING TUNNELING MICROSCOPY; SURFACES; THALLIUM