The relationship between grain boundary structure, defect mobility, and grain boundary sink efficiency

Area of Science:

• Materials Science
• Nanomaterials
• Radiation Effects

Background:

• Nanocrystalline materials offer enhanced functionality and radiation tolerance due to interfaces.
• The exact role of interfaces in defect behavior under irradiation remains unclear.

Purpose of the Study:

• To investigate defect and defect cluster mobility at grain boundaries in copper (Cu) using advanced simulation techniques.
• To elucidate the relationship between interface structure, defect kinetics, and radiation tolerance in nanocrystalline materials.

Main Methods:

• Employed long-time simulation methods to determine defect mobility at grain boundaries in Cu.
• Analyzed the influence of boundary structure and defect cluster size on mobility.
• Correlated defect energetics with atomic site volumes at the boundary.

Main Results:

• Defect mobilities at grain boundaries vary significantly with boundary structure and cluster size.
• Larger defect clusters exhibit reduced mobility compared to smaller ones.
• Interface sink efficiency is dependent on defect kinetics and the in-boundary annihilation rate, influenced by evolving boundary structure.

Conclusions:

• Interface properties, specifically defect mobility and sink efficiency, are crucial for radiation tolerance in nanocrystalline materials.
• Defect mobility at grain boundaries can be slower than in the bulk, impacting overall material performance.
• Understanding defect-interface interactions is key to designing radiation-tolerant nanocrystalline materials.