Critical systematic investigation of the Cd–Ce system: phase stability and Gibbs energies of formation and equilibria via thermodynamic description

Abstract

Abstract The CALPHAD (CAlculation of PHAse Diagrams) technique is used in the critical remodeling of the Cd–Ce system. On the basis of new experimental data in the literature, the excess Gibbs energies of the solution phase expression (liquid, bcc, fcc, and hcp_A3) are described using the Redlich–Kister equation. Four compounds (Cd3Ce, Cd6Ce, Cd11Ce, and Cd17Ce2) are treated as stochiometric compounds. Two intermetallic compounds (Cd2Ce and Cd58Ce13), which exhibit a little homogeneity range, are treated as a two-sublattice model. Two thermodynamic models are used for the CdCe and bcc. Model I is to model the compound CdCe and bcc-Ce separately. Model II is to use the formula (Cd, Ce)0.5(Cd, Ce)0.5(Va)3 to describe the compound CdCe with a CsCl-type structure (B2) and cope with the disorder–order transition from bcc-A2 to bcc-B2. The present work shows that four eutectic reactions, three peritectic reactions, two eutectoid reactions, one peritectoid transformation and three congruent reactions are observed, and the stoichiometric compound Cd17Ce2 is only stable from 804 to 882 °C in the Cd–Ce system.