A thermodynamic description of the Ce–La–Mg system

Abstract

Abstract The thermodynamic optimization of the Ce–La and Ce–La–Mg systems has been carried out using the CALPHAD technique. The solution phases (liquid, bcc, fcc, hcp and dhcp) were described with a substitutional solution model. The isostructural compounds MgCe in the Ce–Mg system and MgLa in the La–Mg system with B2 structure form a continuous range of solid solution in the Ce–La–Mg system. The order–disorder transition between the solutions with A2 structure and compounds with B2 structure in the system has been taken into account and thermodynamically modeled. The other isostructural compounds Mg12Ce and Mg12La, Mg17Ce2 and Mg17La2, Mg41Ce5 and Mg41La5, Mg3Ce and Mg3La, and Mg2Ce and Mg2La were described as such formula Mg12(Ce, La), Mg17(Ce, La)2, Mg41(Ce, La)5, Mg3(Ce, La, Mg), Mg2(Ce, La), respectively. A set of self-consistent thermodynamic description of the Ce–La–Mg system was obtained.