Growth and surface alloying of Fe on Pt(997)

TL;DR

This study investigates the growth behavior and surface alloying of iron on a platinum surface using scattering and spectroscopy techniques across a range of temperatures, revealing distinct growth regimes and alloy formation processes.

Contribution

It provides new insights into temperature-dependent growth modes and alloying mechanisms of Fe on Pt(997), highlighting the role of step density and temperature.

Findings

Below 450K, smooth monolayer formation occurs.

At 500K-550K, surface alloy forms.

Above 600K, bulk alloying initiates.

Abstract

The growth of ultra-thin layers of Fe on the vicinal Pt(997) surface is studied by thermal energy He atom scattering (TEAS) and Auger electron spectroscopy (AES) in the temperature range between 175K and 800K. We find three distinct regimes of qualitatively different growth type: Below 450K the formation of a smooth first monolayer, at and above 600K the onset of bulk alloy formation, and at intermediate temperature 500K - 550K the formation of a surface alloy. Monatomic Fe rows are observed to decorate the substrate steps between 175K and 500K. The importance of the high step density is discussed with respect to the promotion of smooth layer growth and with respect to the alloying process and its kinetics.