(1) Universität Osnabrück, Fachbereich Physik, 49069 Osnabrück, Germany;(2) LPCQ, University M. Mammeri, 15000 Tizi-Ouzou, Algeria;(3) Physik Department E13/FRM II, TU München, 85747 Garching, Germany
Abstract:
We present atomic-scale computer simulations in equiatomic L10-CoPt where Molecular Dynamics and Monte Carlo techniques have both been applied to study the vacancy-atom exchange and kinetics relaxation. The atomic potential is determined using a Tight-Binding formalism within the Second-Moment Approximation. It is used to evaluate the different saddle-point energies involved in a vacancy-atom exchange between nearest-neighbour sites. The potential and the saddle-point energies have been used to simulate the relaxation of the long-range order in CoPt using a Monte Carlo technique. A vacancy migration energy of 0.73±0.15 eV and an order-disorder transition temperature of 935 K have been found.