How superheated crystals melt

The melting of superheated crystalline solids through the penetration of intense radiation within at a temperature above the equilibrium melting temperature was investigated. The atomistic simulations, relevant for aluminum, was used to show that the thermal fluctuation initiating melting is an aggregate typically with 6-7 interstitials and 3-4 vacancies. Vacancy-interstital pairs were created through thermal fluctuation and interstitial-vacancy pairs were created close to the interstitial aggregate. It was found that when a defect aggregate contains more than about 10 point defects, it usually grows rapidly and irreversibly.