Structure of screw dislocation core in Ta at high pressure

Journal Article · Fri Mar 07 04:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4867520· OSTI ID:22277947

Wang, Shaofeng; Jiang, Na; Wang, Rui; Zhou, Ying ^[1]

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1. Institute for Structure and Function and Department of Physics, Chongqing University, Chongqing 400030 (China)

The core structure and Peierls stress of the 1/2 〈111〉(110) screw dislocation in Ta have been investigated theoretically using the modified Peierls–Nabarro theory that takes into account the discreteness effect of crystal. The lattice constants, the elastic properties, and the generalized-stacking-fault energy(γ-surface) under the different pressures have been calculated from the electron density functional theory. The core structure of dislocation is determined by the modified Peierls equation, and the Peierls stress is evaluated from the dislocation energy that varies periodically as dislocation moves. The results show the core width and Peierls stress in Ta are weakly dependent of the pressure up to 100 GPa when the length and stress are measured separately by the Burgers vector b and shear modulus μ. This indicates that core structure is approximately scaling invariant for the screw dislocation in Ta. The scaled plasticity of Ta changes little in high pressure environment.

• OSTI ID: 22277947
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 9 Vol. 115; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
APPROXIMATIONS
CRYSTALS
ELASTICITY
ELECTRON DENSITY
LATTICE PARAMETERS
PERIODICITY
PLASTICITY
PRESSURE DEPENDENCE
SCREW DISLOCATIONS
SHEAR PROPERTIES
STACKING FAULTS
STRESSES
SURFACES
TANTALUM