Charge-optimized many-body potential for the hafnium/hafnium oxide system

A dynamic-charge, many-body potential function is proposed for the hafnium/hafnium oxide system. It is based on an extended Tersoff potential for semiconductors and the charge-optimized many-body potential for silicon oxide. The materials fidelity of the proposed formalism is demonstrated for both hafnium metal and various hafnia polymorphs. In particular, the correct orders of the experimentally observed polymorphs of both the metal and the oxide are obtained. Satisfactory agreement is found for the structural and mechanical properties, defect energetics, and phase stability as compared to first-principles calculations and/or experimental values. The potential can be used in conjunction with the previously determined potentials for the Si and SiO₂ system. This transferability is demonstrated by comparing the structure of a hafnia/silicon interface to that previously determined from electronic-structure calculations.