Electron reflectivity measurements of Ag adatom concentrations on W(110)

TL;DR

This paper introduces a LEEM-based method to measure Ag adatom densities on W(110), enabling detection of minute changes and providing insights into sublimation and condensation behaviors at various temperatures.

Contribution

It demonstrates a sensitive LEEM technique for quantifying Ag adatom densities and studying their temperature-dependent sublimation and condensation on W(110).

Findings

High sensitivity detection of adatom density changes (as small as 10$^{-3}$ ML)

Measurement of Ag sublimation rates at high temperatures

Determination of adatom density dependence on temperature during condensation

Abstract

The density of two-dimensional Ag adatom gases on W(110) is determined by monitoring local electron reflectivity using low energy electron microscopy (LEEM). This method of adatom concentration measurement can detect changes in adatom density at least as small as 10$^{-3}$ ML for a $\mu$m size region of the surface. Using this technique at high temperatures, we measure the sublimation rates of Ag adatoms on W(110). At lower temperatures, where Ag adatoms condense into monolayer islands, we determine the temperature dependence of the density of adatoms coexisting with this condensed phase and compare it with previous estimates.