Al Dimer Dynamics on Al(111)

Abstract
Al dimer dynamics on Al(111) at equilibrium and under compression is studied using first-principles density-functional theory calculations. A smooth potential energy surface provides a long-range attraction between the dimer atoms and leads to a substantial temperature window in which dissociation is frozen and exotic dimer dynamics is observed. Surface relaxations play a prominent role in the uncovering of an unexpected ground state and a new diffusion path. A way of affecting growth by compression is illustrated. The possibility of a metal quantum rotor is addressed and further examined using effective-medium theory calculations.