First-principles calculations on Mg/Al4C3 interfaces

► We study Al4C3 slabs and Mg(0 0 0 2)/Al4C3(0 0 0 1) interfaces with a DFT-GGA method. ► C-terminated Al4C3(0 0 0 1) slabs is more active than that of Al-terminated slabs. ► C-terminated “OT” structure is the most stable Mg(0 0 0 2)/Al4C3(0 0 0 1) interface. ► Interfacial energy of Mg/Al4C3 interfaces do not depend on Al chemical potential. ► Al4C3 particle is effective heterogeneous nucleation substrate for α-Mg.