LAUSR

Melting and crystallization are fundamental and practically important first-order phase transitions in condensed-matter physics, material science and climate change, yet a detailed understanding of their relevant kinetic pathways is still evolving [1,2]. To date, many theoretical models have been developed from homogeneous classical nucleation theory (CNT) model, but they rarely address the exact preferential nucleating sites and the potentially relevant role played by defects, surfaces, dimensionality and their combinations in phase transformations [3]. Recently, Samanta et al. conducted large-scale atomistic calculation of a phase transformation process of a metal from solid to liquid and predicted that the process takes place via multiple competing pathways involving the formation and migration of point defects or dislocations [4]. Although these calculations indeed provide a rare look at real phase transformations, much confusion still exists regarding the atomistic understanding of a dynamic process of a phase transformation due to the lack of direct experimental observations at the atomic scale as well as due to the experimental intricacies in tackling such a challenging topic.