Disentangling interatomic repulsion and anharmonicity in the viscosity and fragility of glasses
| Autor: | Konrad Samwer, Alessio Zaccone, Johannes Krausser, A.E. Lagogianni |
|---|---|
| Přispěvatelé: | Apollo - University of Cambridge Repository |
| Rok vydání: | 2017 |
| Předmět: |
FOS: Physical sciences
02 engineering and technology Condensed Matter - Soft Condensed Matter 01 natural sciences Condensed Matter::Disordered Systems and Neural Networks Viscosity Fragility 0103 physical sciences Physics::Atomic and Molecular Clusters 010306 general physics Physics cond-mat.soft Condensed Matter::Quantum Gases Condensed Matter - Materials Science Condensed matter physics Anharmonicity Materials Science (cond-mat.mtrl-sci) 021001 nanoscience & nanotechnology cond-mat.mtrl-sci 3. Good health Condensed Matter - Other Condensed Matter Condensed Matter::Soft Condensed Matter cond-mat.other Soft Condensed Matter (cond-mat.soft) 0210 nano-technology Other Condensed Matter (cond-mat.other) |
| DOI: | 10.48550/arxiv.1703.06457 |
| Popis: | Within the shoving model of the glass transition, the relaxation time and the viscosity are related to the local cage rigidity. This approach can be extended down to the atomic-level in terms of the interatomic interaction, or potential of mean-force. We applied this approach to both real metallic glass-formers and model Lennard-Jones glasses. The main outcome of this analysis is that in metallic glasses the thermal expansion contribution is mostly independent of composition and is uncorrelated with the interatomic repulsion: as a consequence, the fragility increases upon increasing the interatomic repulsion steepness. In the Lennard-Jones glasses, the scenario is opposite: thermal expansion and interatomic repulsion contributions are strongly correlated, and the fragility decreases upon increasing the repulsion steepness. This framework allows one to tell apart systems where "soft atoms make strong glasses" from those where, instead, "soft atoms make fragile glasses". Hence, it opens up the way for the rational, atomistic tuning of the fragility and viscosity of widely different glass-forming materials all the way from strong to fragile. Comment: arXiv admin note: text overlap with arXiv:1608.03834 |
| Databáze: | OpenAIRE |
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