Formation of Pt induced Ge atomic nanowires on Pt/Ge(001): a DFT study

TL;DR

This study uses density functional theory to investigate the atomic structures of Pt-induced Ge nanowires on Pt/Ge(001), revealing that nanowires are composed of Ge atoms formed due to Pt surface atom enrichment.

Contribution

It provides a detailed theoretical analysis of the atomic structure and formation mechanism of Ge nanowires induced by Pt on Ge(001), supported by comparison with experimental STM data.

Findings

Nanowires are composed of Ge atoms, not Pt.

Formation driven by increased Pt concentration in Ge surface layers.

Theoretical structures match experimental STM images.

Abstract

Pt deposited onto a Ge(001) surface gives rise to the spontaneous formation of atomic nanowires on a mixed Pt-Ge surface after high temperature annealing. We study possible structures of the mixed surface and the nanowires by total energy (density functional theory) calculations. Experimental scanning tunneling microscopy images are compared to the calculated local densities of states. On the basis of this comparison and the stability of the structures, we conclude that the formation of nanowires is driven by an increased concentration of Pt atoms in the Ge surface layers. Surprisingly, the atomic nanowires consist of Ge instead of Pt atoms.