A reactive force-field for Zirconium and Hafnium Di-Boride

Zirconium and Hafnium Di-Boride are the two major material systems that are of critical importance for applications in ultra-high temperature environments where both oxidation and mechanical damage mechanisms (such as creep) are operative. Atomistic simulations of these materials at finite temperatures have been hampered due to the unavailability of inter-atomic potentials for the involved elements. In this paper, we present the development of interatomic potentials for both ZrB₂ and HfB₂ within the ReaxFF framework - thus enabling modeling of chemical reactions. The parameters of the reactive force field are derived by fitting to detailed quantum mechanical simulations of ZrB₂ and HfB₂ clusters and crystal structures.