Inward motion of diamond nanoparticles inside an iron crystal

Area of Science:

• Materials Science
• Solid-State Physics
• Nanotechnology

Background:

• Solid particles typically remain on surfaces without mechanical loading.
• Understanding particle-solid interactions is crucial for materials engineering.

Purpose of the Study:

• To investigate particle penetration into solids without external force.
• To elucidate the mechanism behind this unusual mass transport.

Main Methods:

• In situ microscopic experiments.
• Bulk experiments.
• Utilizing diamond nanoparticles (~100 nm) and iron.

Main Results:

• Diamond nanoparticles penetrated iron to millimeter depths at elevated temperatures (half the melting point).
• Particle motion was displacive and whole-body.
• A local stress, induced by diffusing iron atoms via interfacial channels, drove the motion.

Conclusions:

• Demonstrated an unprecedented mode of mass transport in solids.
• This mechanism differs from conventional atomic diffusion.
• Highlights the importance of interfacial phenomena in solid-state dynamics.