Calculation of solid–liquid interfacial free energy and its anisotropy in undercooled system

The solid–liquid interfacial free energy and its anisotropy are crucial quantities in determining the microstructure and mechanical properties of materials. However, most researches mainly concerned the solid–liquid coexistence at melting point. In this work, two methods, the critical nucleus method (CNM) and the capillary fluctuation method (CFM), were combined to get these quantities in undercooled system by molecular dynamics (MD) simulations. The melting point, Tolman length, interfacial free energy and its anisotropy were calculated, and good consistent results from these two methods are obtained. The results of interfacial free energy obtained by CNM and CFM are 103.79 and 102.13 mJ·m−2, respectively, with the error <2%. Meanwhile, both of the methods provide the rank of interfacial free energy by γ100 > γ120 > γ110 > γ112 > γ111. The results of the present study are also in good agreement with experimental data and computational data in the literature.