Nucleation transition and nucleus density scaling in surfactant-mediated epitaxy

作者：Wang DM^*; Ding ZJ; Sun X

来源：Physical Review B, 2005, 72(11): 115419.

DOI：10.1103/PhysRevB.72.115419

A model of submonolayer epitaxial growth mediated by a monolayer of surfactant is studied, where exchange of adatoms with their underneath surfactant atoms is reversible; i.e., an exchanged adatom can reexchange with the lifted surfactant atom to return to the top of the surfactant layer when the substrate temperature is high enough. A rate equation analysis shows that island nucleation governed by the reexchanging-controlled surface diffusion obeys a scaling law, which connects the nucleation density with the rates of the deposition, surface diffusion, exchange, and reexchange process. Our model system reveals distinct nucleation transitions due to the activated exchange and reexchange, and the nucleation density as a function of temperature exhibits a characteristic N shape with a minimum and a maximum, which define the transition temperatures. The analytical results are confirmed by comparison with kinetic Monte Carlo simulations.

• 出版日期2005-9
• 单位阜阳师范学院