A simple model for orientational ordering of a silver monolayer electrodeposited on a C(0001) surface

E.E. MOLA; G. A. APPIGNANESI; J.L. VICENTE; L. VAZQUEZ; R.C. SALVAREZZA; A.J. ARVIA

SURFACE REVIEW AND LETTERS

WORLD SCIENTIFIC PUBL CO PTE LTD

Año: 1995 vol. 2 p. 489 - 494

0218-625X

The model for the angular orientational energy (AOE) has been extended to hexagonal submonolayer domains of Ag electrodeposited at a constant overpotential on a C(0001) surface. These domains which are characterized by an epitaxy angle è=15±5° and an Ag-Ag distance dAg-Ag=0.330± 0.016 nm, can be considered as precursors of 3D Ag crystal formation, according to a Volmer-Weber type mechanism. Calculations are based upon a simple Hamiltonian evaluated by introducing the concept of the commensurable unit cell. A Fourier series expansion for the substrate potential was used. Results from the model predict the existence of a commensurable cell in agreement with the experimental data derived from STM imaging.