Relativistic peculiarities at stepped surfaces: surprising energetics and unexpected diffusion patterns

TL;DR

This paper investigates the unique adsorption and diffusion behaviors of 5d metal adatoms on stepped surfaces, revealing that relativistic effects cause these metals to favor edge adsorption, contrasting with 3d and 4d metals.

Contribution

The study provides the first ab initio explanation for the relativistic influence on adatom energetics and diffusion patterns on stepped surfaces of 5d metals.

Findings

5d adatoms prefer edge adsorption due to relativistic effects

Contrasts with 3d and 4d metal behaviors

Relativity directly influences surface energetics

Abstract

We revive intriguing, yet still unexplained, experimental results of Ehrlich and co-workers [ Phys. Rev. Lett. 77 1334 (1996); Phys. Rev. Lett. 67 2509 (1991)] who have observed, that 5d adatoms distributed on (111) surface islands of 5d metals favor the adsorption at the cluster's edge rather than at the cluster's interior, which lies in contrast with the behavior of 4d and 3d elements. Our state of the art ab initio calculations demonstrate that such behavior is a direct consequence of the relativity of 5d metals.