Related Experiment Video
Updated: Jul 16, 2025

Characterization of Ultra-fine Grained and Nanocrystalline Materials Using Transmission Kikuchi Diffraction
Published on: April 1, 2017
Interplay of Mechanochemistry and Material Processes in the Graphite to Diamond Phase Transformation
Brenden W Hamilton1, Timothy C Germann1
1Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
None:
The manifestation of intramolecular strains in covalent systems is widely known to accelerate chemical reactions and open alternative reaction paths. This process is moderately well understood for isolated molecules and unimolecular processes. However, in condensed matter processes such as phase transformations, material properties and structure may influence typical mechanochemical effects. Therefore, we utilize steered molecular dynamics to induce out of plane strains in graphite and compress the system under a constant strain rate to induce phase transformation. We show that the out of plane strain allows phase transformations to initiate at small amounts of compressive strain. However, in contrast to typical mechanochemical results, the sum of compressive and out of plane work needed to form a diamond has a local minimum due to altered defect formation processes during phase transformation. Additionally, these altered processes slow the kinetics of the phase transformation, taking longer from initiation to total material transformation.
Related Concept Videos
Network Covalent Solids
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
Phase Transitions: Sublimation and Deposition
Phase Transitions
Phase Transitions: Melting and Freezing
States of Matter and Phase Changes
Phase Transitions: Vaporization and Condensation

