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MM: Fachverband Metall- und Materialphysik
MM 6: Interfaces II
MM 6.2: Vortrag
Montag, 26. März 2007, 12:00–12:15, H6
Bond-order potential for atomistic modeling of extended defects in tungsten — •Matous Mrovec1,2, Christian Elsaesser1,2, and Peter Gumbsch1,2 — 1IZBS, University of Karlsruhe, Kaiserstr. 12, 76131 Karlsruhe — 2Fraunhofer-Institute IWM, Woehlerstr. 11, 79108 Freiburg
The bond-order potential (BOP) for transition metals is a real-space semi-empirical description of interactions between atoms, which is based on the tight-binding approximation and the d-band model. This scheme provides a direct bridge between the electronic-structure modeling and the atomistic modeling by coarse-graining the electronic degrees of freedom into a many-body interatomic potential. We will present a recently constructed BOP for the body-centered cubic transition metal tungsten. The potential was extensively tested against accurate DFT methods in order to assess its reliability and applicability. The high predictive power of the BOP will be demonstrated in studies of extended defects, namely low-index surfaces, symmetrical tilt grain boundaries, and lattice dislocations, which all affect the mechanical behavior of polycrystalline tungsten.