Liquid-phase thermodynamics and structures in the Cu–Nb binary system

Abstract

An embedded atom method (EAM) interatomic potential is constructed to reproduce the main topological features of the experimental equilibrium phase diagram of the Cu–Nb system in both solid and liquid states. The potential is fitted to composition-dependent enthalpies of mixing for bcc and fcc random solid solutions obtained from first-principles calculations at 0 K. Compared with two other EAM Cu–Nb potentials in the literature, the phase diagram of the current potential shows better agreement with the experimental phase diagram. Our potential predicts that the Cu–Nb liquid phase at equilibrium is compositionally patterned over lengths of about 2.3 nm. The newly constructed potential may be used to study the effect of liquid thermodynamics and structure on properties of binary systems, such as radiation-induced mixing.