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Mechanism for the amorphisation of diamond
Barbara A Fairchild1, Sergey Rubanov, Desmond W M Lau
1University of Melbourne, Melbourne, Australia. babs@physics.unimelb.edu.au
Advanced Materials (Deerfield Beach, Fla.)
|March 16, 2012
Summary
Diamond lattice breakdown is strain-driven, not damage-driven. The diamond structure remains stable until 16% of atoms are displaced, revealing a critical strain threshold for amorphization.
Area of Science:
- Materials Science
- Solid-State Physics
- Computational Materials Science
Background:
- The diamond lattice is a fundamental structure in materials science.
- Understanding lattice stability under stress is crucial for material applications.
- Previous studies have focused on damage-driven lattice breakdown.
Purpose of the Study:
- To investigate the mechanism of diamond lattice breakdown under ion implantation.
- To differentiate between strain-driven and damage-driven lattice destabilization.
- To determine the critical atomic displacement threshold for diamond amorphization.
Main Methods:
- Utilizing ion implantation techniques to introduce atomic displacements.
- Employing molecular dynamics simulations to model lattice behavior.
- Analyzing atomic configurations and stress distributions during simulation.
Main Results:
- Demonstrated that lattice breakdown is primarily driven by strain, not direct atomic damage.
- Identified that the diamond lattice remains intact until 16% of atoms are removed from lattice sites.
- Observed a clear transition from crystalline diamond to amorphous carbon.
Conclusions:
- Strain accumulation is the dominant factor leading to diamond lattice breakdown.
- The 16% atomic displacement threshold provides a quantitative measure for lattice stability.
- Findings offer insights into the amorphization process of covalent materials.
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