Role of core polarization curvature of screw dislocations in determining the Peierls stress in bcc Ta: A criterion for designing high-performance materials

摘要

We use a family of embedded atom model potentials all based on accurate quantum-mechanical calculations to study the relation between Peierls stress and core properties of the 1/2a‹111› screw dislocation in bcc tantalum (Ta). We find that the Peierls stress (σP) is a function of the core-polarization curvature (II) near the equilibrium core configuration. Our results suggest that the computationally available quantity II is a useful criterion for designing high-performance materials.