Berlin 2008 – scientific programme

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SYMS: Symposium Modern developments in multiphysics materials simulations

SYMS 3: Modern developments in multiphysics materials simulations III

SYMS 3.4: Talk

Friday, February 29, 2008, 11:00–11:15, A 053

Magnetic Bond-order Potential: Application to Defect Behavior — •Matous Mrovec^1,2, Duc Nguyen-Manh³, Christian Elsaesser^1,2, Peter Gumbsch^1,2, and David Pettifor⁴ — ¹IZBS, University of Karlsruhe, Kaiserstr. 12, 76131 Karlsruhe — ²Fraunhofer-Institute for Mechanics of Materials IWM,Wöhlerstr. 11, 79108 Freiburg, Germany — ³EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom — ⁴Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom

Development of reliable interatomic potentials for simulations of structural defects in iron and iron-based materials presents a significant challenge. Energetics and structural stability of magnetic materials is strongly influenced by magnetic effects and details of the Fermi surface. These materials are therefore described rather poorly by the embedded-atom-method or Finnis-Sinclair-type potentials, which are only density dependent. We present a bond-order potential (BOP) for iron, which is based on a tight-binding bond representation. The model is able to capture the directional character of bonds present in transition metals and includes a description of magnetic effects within the Stoner model of tinerant magnetism. The constructed BOP is applied in studies of point defects, dislocations, and grain boundaries in ferromagnetic iron.