Local chemical ordering within the incubation period as a trigger for nanocrystallization of a highly supercooled Ti-based liquid

Highlights: • The nature of incubation period studied from both the theoretical and experimental viewpoint. • Nanocrystallization with elemental mapping at near-atomic resolution sheds light on the nature of the incubation period. • Molecular dynamics illustrates the nucleation process and supports the results. • Nanometer-range chemical rearrangements reduce the energy barrier versus crystallization. In the present work we study nanocrystallization of the Ti₅₀Ni₂₃Cu₂₂Sn₅ alloy within the supercooled liquid region by using a state-of-the-art experimental technique with elemental mapping at near-atomic resolution especially focusing on the incubation period which is still poorly understood from both the theoretical and experimental viewpoint. Molecular dynamics (MD) simulation results performed for the Ti₅₅Ni₄₅ liquid acting as a simplified model system of the (Ti,Sn)₅₅(Ni,Cu)₄₅ alloy illustrate the process of nucleation and provide some additional suggestions. The experiment and MD results indicate formation of nanometer-range chemical rearrangements which are supposed to reduce the energy barrier in the complex energy landscape finally leading to a high density of homogeneously nucleating crystallites after the completion of a macroscopically observed incubation period.