Electron-stimulated sputtering of thin amorphous solid water films on Pt(111)

Area of Science:

• Materials Science
• Surface Science
• Physical Chemistry

Background:

• Amorphous solid water films are relevant in various scientific fields.
• Understanding electron-matter interactions is crucial for surface processes.
• Pt(111) serves as a well-defined model substrate for surface studies.

Purpose of the Study:

• Investigate electron-stimulated sputtering of amorphous solid water films on Pt(111).
• Differentiate between electron-stimulated desorption and reaction pathways.
• Determine the influence of film thickness and temperature on sputtering yield.

Main Methods:

• Deposition of thin amorphous solid water films on a Pt(111) substrate.
• Exposure to electron beams to induce sputtering.
• Analysis of sputtering products (H2, O2, H2O).
• Variable film thickness and temperature experiments.

Main Results:

• Sputtering is dominated by water molecule desorption and reactions forming H2 and O2.
• Water desorption increases with film thickness.
• Total sputtering yield peaks at intermediate film thicknesses.
• Reactions occur at both water/vacuum and Pt/water interfaces.
• Significant hydrogen loss observed at the Pt/water interface using D2O/H2O layered films.
• Sputtering is temperature-independent below 80 K and increases at higher temperatures.

Conclusions:

• Electron-stimulated sputtering of water on Pt(111) is a complex process involving desorption and reactions.
• Film thickness critically influences sputtering mechanisms and yield.
• Interface reactions, particularly at the Pt/water interface, play a significant role in film erosion and hydrogen loss.