Simulations of cementite: An analytical potential for the Fe-C system

An analytical bond-order interatomic potential has been developed for the iron-carbon system for use in molecular-dynamics and Monte Carlo simulations. The potential has been successfully fitted to cementite and H\"agg carbide, which are most important crystalline polytypes among the many known metastable iron carbide phases. Predicted properties of other carbides and the simplest point defects are in good to reasonable agreement with available data from experiments and density-functional theory calculations. The potential correctly describes melting and recrystallization of cementite, making it useful for simulation of steels. We show that they correctly describe the metastability of cementite and can be used to model carbide growth and dissolution.