Surface mobility in amorphous selenium and comparison with organic molecular glasses.

Area of Science:

• Materials Science
• Surface Science
• Solid-State Chemistry

Background:

• Surface diffusion is crucial for processes on amorphous solid surfaces, including crystallization.
• Understanding surface dynamics is key to controlling material properties and reactions.
• Previous studies established a power law for surface diffusion in molecular glasses.

Purpose of the Study:

• To quantify surface dynamics of amorphous selenium using atomic force microscopy.
• To investigate the relationship between surface diffusion and surface crystallization in amorphous selenium.
• To determine if the established power law applies to inorganic polymer glasses.

Main Methods:

• Monitoring the temporal evolution of nanoholes on amorphous selenium surfaces.
• Utilizing Atomic Force Microscopy (AFM) for high-resolution surface analysis.
• Quantifying surface diffusion coefficients and surface crystal growth rates.

Main Results:

• The surface diffusion coefficient of amorphous selenium was successfully quantified.
• A power law relationship (u_s ≈ D_s ^0.87) was observed between surface diffusion and surface crystallization rate.
• This power law was found to be consistent with previous findings in molecular glasses.

Conclusions:

• The study validates the power law scaling for surface crystallization in amorphous selenium, an inorganic polymer glass.
• Surface diffusion coefficient serves as a reliable predictor for surface crystallization rates.
• The findings have broad implications for understanding and predicting surface processes in diverse materials.