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On the shapes of weakly adsorbed two-dimensional clusters
A257 Surface Science 97 (1980) 537-552 D North-Holland Publishing Company ON THE SHAPES OF WEAKLY ADSORBED TWO-DIMENSIONAL Giuseppe DEL RE, Vincenzo BARONE and Nicola MONTELLA Cattadra di Chimica Teorica, Universitti di Napoli, Via Mezzocannone
CLUSTERS
4, I-80134 Napoli, Italy
and AndrC JULG Laboratoire de Chimie Thkorique,
UniversitP de Provence, F-13331
Marseille Ckdex 3, France
Received 5 October 1979; accepted for publication 24 March 1980 A simple iterative method previously applied to study distortions induced by boundaries in finite clusters is applied to the study of the geometrical relaxation of model two dimensional islands of univalent metals, weakly adsorbed on a substrate. Particular attention is devoted to the formation of one or two vacancies by partial desorption. The rearrangement results in the formation of “ghost-vacancies” surrounding the site where an atom was removed, and/or pieces of a distorted triangular lattice. In some cases the islands are practically divided into subunits. The general picture obtained for the adsorbed phase is a system of non-interacting distorted islands, whose shapes result from competition between “memory” of the shape prior to formation of vacancy, tendency to form a triangular lattice, and tendency of each atom to form a well defined number of bonds.
Surface Science 97 (1980) 553-563 0 North-Holland Publishing Company STRANSKI-KRASTANOV INVESTIGATION
GROWTH MODE OF Au ON Mo(ll0)
SURFACE:
BY AUGER ELECTRON SPECTROSCOPY
Eveline GILLET and Bernard GRUZZA Luboratoire de Microscopic et Diffractions Electroniques, ERA No. 545, FacultP des Sciences et Techniques de Saint JWme, F-13397 Marseille CPdex 4. France
Received 2 February 1980
This paper is a continuation of the gold condensation on Mo(ll0) study, in which we pointed out the influence of temperature deposition T, on the first stages of growth. The aim of the present work is to study correlations between temperature and growth mode for 293 < 7’, < 1223 K. An analysis of gold AES intensity variation agains coverage showed four different growth modes corresponding to four temperature ranges: 293 < Ts < 773 K: Frank-van der Merwe growth mode (complete or not). 773 < T, < 973 K: Stranski-Krastanov growth mode by a 2D-3D transformation. 973 < T, < 1123 K: Stranski-Krastanov growth mode by nucleation on the first monolayer (complete or not). T, > 1223 K: The sticking coefficient is lower than unity and one monolayer condense after a very long time.
CLUSTERS
4, I-80134 Napoli, Italy
and AndrC JULG Laboratoire de Chimie Thkorique,
UniversitP de Provence, F-13331
Marseille Ckdex 3, France
Received 5 October 1979; accepted for publication 24 March 1980 A simple iterative method previously applied to study distortions induced by boundaries in finite clusters is applied to the study of the geometrical relaxation of model two dimensional islands of univalent metals, weakly adsorbed on a substrate. Particular attention is devoted to the formation of one or two vacancies by partial desorption. The rearrangement results in the formation of “ghost-vacancies” surrounding the site where an atom was removed, and/or pieces of a distorted triangular lattice. In some cases the islands are practically divided into subunits. The general picture obtained for the adsorbed phase is a system of non-interacting distorted islands, whose shapes result from competition between “memory” of the shape prior to formation of vacancy, tendency to form a triangular lattice, and tendency of each atom to form a well defined number of bonds.
Surface Science 97 (1980) 553-563 0 North-Holland Publishing Company STRANSKI-KRASTANOV INVESTIGATION
GROWTH MODE OF Au ON Mo(ll0)
SURFACE:
BY AUGER ELECTRON SPECTROSCOPY
Eveline GILLET and Bernard GRUZZA Luboratoire de Microscopic et Diffractions Electroniques, ERA No. 545, FacultP des Sciences et Techniques de Saint JWme, F-13397 Marseille CPdex 4. France
Received 2 February 1980
This paper is a continuation of the gold condensation on Mo(ll0) study, in which we pointed out the influence of temperature deposition T, on the first stages of growth. The aim of the present work is to study correlations between temperature and growth mode for 293 < 7’, < 1223 K. An analysis of gold AES intensity variation agains coverage showed four different growth modes corresponding to four temperature ranges: 293 < Ts < 773 K: Frank-van der Merwe growth mode (complete or not). 773 < T, < 973 K: Stranski-Krastanov growth mode by a 2D-3D transformation. 973 < T, < 1123 K: Stranski-Krastanov growth mode by nucleation on the first monolayer (complete or not). T, > 1223 K: The sticking coefficient is lower than unity and one monolayer condense after a very long time.