Diffusion of Pt dimers on Pt(111)

TL;DR

This study uses density-functional theory to analyze the diffusion behavior of Pt dimers on Pt(111), revealing their mobility and detailed diffusion pathways, with results matching experimental activation energies.

Contribution

It provides a first-principles calculation of Pt dimer diffusion on Pt(111), identifying the diffusion mechanism and confirming experimental activation energy.

Findings

Activation energy of 0.37 eV matches experiment.

Pt dimers are mobile at relevant temperatures.

Diffusion involves one-atom and concerted two-atom jumps.

Abstract

We report the results of a density-functional study of the diffusion of Pt dimers on the (111) surface of Pt. The calculated activation energy of 0.37 eV is in {\em exact} agreement with the recent experiment of Kyuno {\em et al.} \protect{[}Surf. Sci. {\bf 397}, 191 (1998)\protect{]}. Our calculations establish that the dimers are mobile at temperatures of interest for adatom diffusion, and thus contribute to mass transport. They also indicate that the diffusion path for dimers consists of a sequence of one-atom and (concerted) two-atom jumps.