Pb transport on Si(111)-(7x7) following tip induced imbalance

TL;DR

This study investigates how local tip-induced imbalances affect lead (Pb) transport and nucleation on Si(111)-(7x7), revealing collective density thinning of the wetting layer despite local volume increases.

Contribution

It demonstrates a novel method to induce and observe Pb transport dynamics on Si(111)-(7x7) using scanning force microscopy.

Findings

Local contact causes island height growth and wetting layer density decrease.

Wetting layer exhibits collective density thinning despite local volume increase.

Pb transport dynamics differ from standard theories.

Abstract

Pb on Si(111)-(7x7) shows surprising nucleation and mass transport dynamics at odds with standard theories. To create local imbalances on stable Pb islands we use the tip of a scanning force microscope. We enforce a short, local contact between the island and our tip. The subsequent island height growth and the local contact potential difference are studied via scanning force microscopy and Kelvin probe force microscopy. Though the island has a large volume increase after the contact, we observe that its surrounding wetting layer shows the same Pb density decrease as the global wetting layer. This indicates a collective density thinning of the wetting layer.