Abstract
The disordering of the atomic network of minerals typically results in swelling of the structure. However, the origin of such expansion and the extent thereof remain unclear. Here, we conduct a series of molecular dynamics simulations of vitrification- and irradiation-induced disordering to reveal the nature of disorder-induced expansion in silicate phases. We show that pristine crystals are topologically overconstrained—i.e., some interatomic constraints are mutually redundant. Consequently, the weaker atomic constraints yield to the stronger ones— a behavior that manifests itself through some internal elastic stress in the network. Interestingly, we demonstrate that disordering results in a release of this internal stress by breaking the weaker constraints. The release of such internal strain explains the macroscopic expansion exhibited by atomic networks upon disordering.
| Original language | English |
|---|---|
| Article number | 120846 |
| Journal | Journal of Non-Crystalline Solids |
| Volume | 564 |
| DOIs | |
| State | Published - Jul 15 2021 |
Funding
This research was performed using funding received from the DOE Office of Nuclear Energy's Nuclear Energy University Programs. The authors also acknowledge financial support for this research provided by: The Oak Ridge National Laboratory operated for the U.S. Department of Energy by UT-Battelle (LDRD Award Number: 4000132990 and 4000143356), National Science Foundation (CMMI: 1235269), Department of Science and Technology (DST), India under the INSPIRE faculty scheme (DST/INSPIRE/04/2016/002774), DST SERB Early Career Award (ECR/2018/002228), Indian Institute of Technology Delhi (IITD), and the University of California, Los Angeles (UCLA). Computational resources were provided by the University of California Los Angeles, Indian Institute of Technology Delhi HPC facility, and San Diego Supercomputer Center as part of the HPC@UC program.