Surface Diffusion of a Zn Adatom on a Zn(001) Surface:  A DFT Study

Abstract

The adsorption and diffusion of a Zn atom on a Zn(001) surface has been investigated theoretically by using first-principles periodic boundary condition calculations to elucidate the mechanism of crystal growth of zinc in a Zn surface. Three surface models, terrace, step, and kink, of the Zn(001) surface were considered as adsorption sites in the present study. The most stable site in the terrace model was the on-top site, where the zinc adatom is bound to only one zinc atom of the surface. The activation barrier between the on-top site and the next on-top site was negligibly low (the activation energy is 44 meV at the PW91/LANL2DZ level), suggesting that the Zn adatom diffuses easily on the Zn(001) surface. The Zn adatom was more stabilized at the step site (752 meV) and kink site (935 meV) with respect to the on-top site. It was found that the magnitude of 4s−4p orbital mixing of the Zn adatom (hybridization) is strongly related to the binding energy. The mechanism of the adsorption of Zn on Zn(001) surfaces was discussed on the basis of theoretical results.

Mobility of Sn Atoms and Clusters on Cu(111) Surfaces and Cu2Sn Surface Alloys

“…Such a difference, however, can be explained with the different degree of relaxation of the systems investigated and the different mechanisms of diffusion taken into account, both in favor of the E a,Sn estimate given in the present work. Another indication in this sense comes from the fact that the E a,Sn value obtained is close to the experimental activation energy for the migration of Sn atoms on a Cu(111) surface, equal to about 24.7 kJ mol −1 , and in line with the activation energies for diffusion processes generally reported in the literature …”

Density functional theory for transition metals and transition metal chemistry

“…Iokibe et al 985 studied the adsorption and diffusion of Zn on Zn(001) with the PW91 density functional. Kurzweil and Baer 1094 used a novel DFT approach to study the surface plasmon absorption of Au 8 and Au 18 .…”

“…Sorkin et al 431 found that B3LYP and M05-2X both give reasonable results for the binding energies of small Zn clusters. Iokibe et al 985 found that the bond length and cohesive energy of the clusters depends on the extent of 4s/4p mixing, in contrast to earlier transition metals where 4s/3d mixing is a key quantity.…”

“…Zn clusters have been studied by various workers. Dai et al 984 used PW91, and Iokibe et al 985 used LSDA, PW91, and B3LYP. Sorkin et al 431 found that B3LYP and M05-2X both give reasonable results for the binding energies of small Zn clusters.…”

Multiscale Simulation of Irregular Shape Evolution during the Initial Stage of Zn Electrodeposition on a Negative Electrode Surface

“…Density functional theory (DFT) is utilized in numerous atomic-scale analyses of chemical processes, including solid–liquid interfacial processes. , Adatom surface diffusion and the adsorption of the metal atoms are also analyzed using DFT. − While these studies provide a mechanistic understanding of each process with respect to the electronic state, DFT calculations cannot be used to analyze stochastic phenomena, such as shape evolution over much larger areas. A kinetic Monte Carlo (KMC) simulation is a stochastic simulation that expands the analysis scale from the atomic to the mesoscale to model deposition and nucleation.…”