Stability of Si-interstitial defects: from point to extended defects

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Materials Science

Background:

• Extended interstitial defects influence material properties.
• Understanding defect formation and growth is crucial for materials design.

Purpose of the Study:

• To investigate the growth trends of extended interstitial defects.
• To model the shape evolution of these defects based on their size.

Main Methods:

• Utilized extensive tight-binding and ab initio local density approximation simulations.
• Parametrized defect-formation energy and interstitial capture radius anisotropy.

Main Results:

• Observed a transition in stable defect shape from compact to chainlike to rodlike with increasing interstitials.
• The rodlike 311 defect, originating from (011) chains, stabilizes and elongates as it grows.
• Developed accurate defect-formation energy parameters.

Conclusions:

• Macroscopic defect-growth simulations are enabled by accurate defect energy and capture radius parametrization.
• The study provides insights into the fundamental mechanisms governing interstitial defect evolution in materials.