Nonequilibrium Roughening and Faceting of Interfaces in Driven Alloys

We consider the case of crystalline alloys submitted to an external forcing that produces ballistic atom exchanges. The dynamical stability of precipitate-matrix interfaces is studied by kinetic atomistic Monte Carlo simulations. At steady state, sharp precipitate-matrix interfaces can exhibit kinetic roughening, while diffuse interfaces may develop a surprising kinetic faceting. The latter results in nonequilibrium faceted shapes for precipitates. The possible implications for materials subjected to radiation fields or processed by ion beams are discussed.