Dislocation Structure and Mobility in hcp
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Stanford Univ., CA (United States). Dept. of Mechanical Engineering
- Univ. of Campinas (UNICAMP), Sao Paulo (Brazil). Inst. of Physics
We assess the core structure and mobility of the screw and edge basal-plane dislocations in hcp 4He using path-integral Monte Carlo simulations. Our findings provide key insights into recent interpretations of giant plasticity and mass flow junction experiments. First, both dislocations are dissociated into nonsuperfluid Shockley partial dislocations separated by ribbons of stacking fault, suggesting that they are unlikely to act as one-dimensional channels that may display Lüttinger-liquid-like behavior. Second, the centroid positions of the partial cores are found to fluctuate substantially, even in the absence of applied shear stresses. This implies that the lattice resistance to motion of the partial dislocations is negligible, consistent with the recent experimental observations of giant plasticity. Our results indicate that both the structure of the partial cores and the zero-point fluctuations play a role in this extreme mobility.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC52-07NA27344; SC0010412; 2013/08293-7
- OSTI ID:
- 1326881
- Alternate ID(s):
- OSTI ID: 1266406
- Report Number(s):
- LLNL-JRNL-691477; PRLTAO
- Journal Information:
- Physical Review Letters, Vol. 117, Issue 4; ISSN 0031-9007
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Quantum effects on dislocation motion from ring-polymer molecular dynamics
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journal | October 2018 |
A relativistic coupled-cluster interaction potential and rovibrational constants for the xenon dimer
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journal | August 2017 |
Dislocation Structure and Mobility in Hcp Rare-Gas Solids: Quantum versus Classical
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journal | January 2018 |
Quantum effects on dislocation motion from Ring-Polymer Molecular Dynamics | text | January 2017 |
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