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Atomic structure of grain boundaries in semiconductors studied by electron microscopy (analogy and difference with surfaces)
A600 484
Surface Science 162 (1985) 484-494 North-Holland, Amsterdam
THE CRITICAL EXPONENTS O F T H E A u ( l l 0 ) (1 x 2) ~ (1 × 1) P H A S E TRANSITION J.C. C A M P U Z A N O , G. JENNINGS and R.F. WILLIS Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE, UK Received 1 April 1985; accepted for publication 10 May 1985 We report measurements of the critical exponents fl, "t, p and their amplitude coefficients for the order-disorder phase transition at a clean metal surface, the Au(ll0) (1 × 2) ~ (1 × 1) transition. Experiments were conducted with a new high resolution LEED method, The results show that the phase transition is strictly two-dimensional, belonging to the lsing universality class. We clearly detect the critical scattering peaking above T¢, signaling the breakdown of the Ornstein-Zernike theory.
Surface Science 162 (1985) 495-509 North-Holland, Amsterdam
495
ATOMIC STRUCTURE OF GRAIN BOUNDARIES IN SEMICONDUCTORS STUDIED BY ELECTRON MICROSCOPY (ANALOGY AND DIFFERENCE WITH SURFACES) A. B O U R R E T D R F - Service de Physique/GS, CEN-Grenoble, 85 X, F-38041 Grenoble C~dex, France and J.J. B A C M A N N D~partement de M~tallurgie/SRM, C E N - Grenoble, 85 X, F- 38041 Grenoble C~dex, France Received 1 April 1985; accepted for publication 15 April 1985 The atomic structure of grain boundaries in germanium and silicon has been recently studied using high energy electron-diffraction, high resolution imaging and the ~-fringe method on tilt (011) GBs. The results are examined in view of the data already obtained on clean semiconductor surfaces. It is shown that GBs tend to favour commensurate structures. Complete reconstruction occurs, sometimes forming a superstructure, and restoring the tetracoordination. New structural units typical of each GB geometry are then formed. The importance of defects in this periodic arrangement is emphasized particularly to explain their electrical activity.
Surface Science 162 (1985) 484-494 North-Holland, Amsterdam
THE CRITICAL EXPONENTS O F T H E A u ( l l 0 ) (1 x 2) ~ (1 × 1) P H A S E TRANSITION J.C. C A M P U Z A N O , G. JENNINGS and R.F. WILLIS Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE, UK Received 1 April 1985; accepted for publication 10 May 1985 We report measurements of the critical exponents fl, "t, p and their amplitude coefficients for the order-disorder phase transition at a clean metal surface, the Au(ll0) (1 × 2) ~ (1 × 1) transition. Experiments were conducted with a new high resolution LEED method, The results show that the phase transition is strictly two-dimensional, belonging to the lsing universality class. We clearly detect the critical scattering peaking above T¢, signaling the breakdown of the Ornstein-Zernike theory.
Surface Science 162 (1985) 495-509 North-Holland, Amsterdam
495
ATOMIC STRUCTURE OF GRAIN BOUNDARIES IN SEMICONDUCTORS STUDIED BY ELECTRON MICROSCOPY (ANALOGY AND DIFFERENCE WITH SURFACES) A. B O U R R E T D R F - Service de Physique/GS, CEN-Grenoble, 85 X, F-38041 Grenoble C~dex, France and J.J. B A C M A N N D~partement de M~tallurgie/SRM, C E N - Grenoble, 85 X, F- 38041 Grenoble C~dex, France Received 1 April 1985; accepted for publication 15 April 1985 The atomic structure of grain boundaries in germanium and silicon has been recently studied using high energy electron-diffraction, high resolution imaging and the ~-fringe method on tilt (011) GBs. The results are examined in view of the data already obtained on clean semiconductor surfaces. It is shown that GBs tend to favour commensurate structures. Complete reconstruction occurs, sometimes forming a superstructure, and restoring the tetracoordination. New structural units typical of each GB geometry are then formed. The importance of defects in this periodic arrangement is emphasized particularly to explain their electrical activity.