Smooth Flow in Diamond: Atomistic Ductility and Electronic Conductivity.

Area of Science:

• Materials Science
• Solid-State Physics
• Computational Materials Science

Background:

• Diamond is recognized as a superhard material with inherent stiffness, brittleness, and a wide electronic band gap.
• These properties have traditionally defined its behavior and applications.

Purpose of the Study:

• To investigate the intrinsic structural and electronic properties of diamond under combined shear and compressive strains.
• To challenge the established understanding of diamond's mechanical and electrical characteristics.

Main Methods:

• First-principles computational studies were employed to simulate diamond's behavior.
• Analysis focused on the effects of coexisting large shear and compressive strains.

Main Results:

• Diamond displays unexpected intrinsic structural ductility and electronic conductivity under specific complex loading conditions.
• These conditions suppress brittle fracture, promoting atomistic ductility and plastic flow.
• A concomitant band gap closure occurs, enabling electrical conductivity through deformation-induced channels.

Conclusions:

• The study reveals unprecedented soft-and-conducting modes in diamond under extreme conditions.
• These findings have significant implications for understanding and predicting diamond's anomalous behaviors in extreme environments.