Regensburg 2022 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 23: Computational Materials Modelling: Magnetic & Electrical Properties

MM 23.4: Vortrag

Mittwoch, 7. September 2022, 16:30–16:45, H44

Magnetic bond-order potential for iron-cobalt alloys — •Aleksei Egorov, Aparna Subramanyam, Ralf Drautz, and Thomas Hammerschmidt — ICAMS, Ruhr-Universität Bochum, Bochum, Germany

We present a general-purpose analytic bond-order potential for large-scale simulations of magnetic FeCo alloys. The model is based on a d-valent orthogonal tight-binding Hamiltonian in two-center approximation and an embedding term to account for the s electrons. The BOP is a physical model and therefore requires only a comparably small set of reference data and only a small number of parameters to be optimized. It still provides good transferability to properties of FeCo that we did not include in the fit. We demonstrate the transferability of the FeCo BOP for defect formation energies, vibrational properties, and elastic constants. Due to the explicit treatment of magnetism, our BOP can reproduce the main features of the electronic structure of magnetic and nonmagnetic phases. The predictive power of the FeCo BOP yields a reasonable estimate of the order-disorder transition temperature of magnetic B2-FeCo. Our FeCo BOP also reproduces the dense sequence of stable structures for Fe-rich FeCo compounds.