Multicenter multidomainB1−B2pressure-induced reconstructive phase transition in potassium fluoride

Abstract

The reconstructive pressure-induced phase transformation of potassium fluoride from $B1$ to the high-pressure $B2$ structure type is investigated by means of molecular dynamics simulations. Application of the transition path sampling approach allows investigation the phase transition without driving the kinetics by overcritical pressure or artificial forces along a predefined reaction coordinate. This offers a unique perspective for studying the atomistic mechanisms involved in the nucleation and growth of phases. From our simulations, we demonstrate the ability of investigating coexisting nucleation centers, resulting in the formation of local phase domains. Depending on the respective inset of ionic translocations, local domains may be formed in different manners. In this case, phase growth is observed to lead to domain-domain interfaces, which result in grain boundaries once the phase transition is completed.