Superabundant vacancies in a metal-hydrogen system: Monte Carlo simulations

Abstract

13 pInternational audienceAn equilibrium Monte Carlo simulation capable of treating superabundant vacancy formation and ordering in metal-hydrogen systems (M-H) is developed. It combines lattice site occupations and continuous degrees of freedom which enables one to perform insertion/removal moves and hydrogen-vacancy cluster moves while the position of the particles are sampled. The bulk phase diagram in (μM,NH,V,T) ensemble is estimated for concentrations lower than 1  at. %. Within the framework of an EAM Al-H potential, ordering of superabundant vacancies in the shape of chains and platelets is reported at room temperature