A thermodynamic description of the Cr–Ge system

The phase equilibria and thermodynamic properties of the Cr–Ge system were optimized using the CALPHAD (Calculation of Phase Diagram) technique. In the present work, the excess Gibbs energy of the liquid, body-centered cubic (bcc) and diamond solution phases were modeled with the Redlich–Kister equation. The excess Gibbs energies for the solution phases (liquid, bcc, diamond) were described using the polynomial temperature dependence and Kaptay equation. The intermetallic compounds Cr3Ge, αCr5Ge3 and βCr5Ge3, which had homogeneity ranges, were treated with sublattice models Cr3(Cr, Ge), α(Cr, Ge)5Ge3 and β(Cr, Ge)5Ge3, respectively. The intermetallic compounds Cr11Ge8, CrGe and Cr11Ge19 were treated as stoichiometric compounds. Two sets of self-consistent thermodynamic parameters were obtained and the calculated results were presented and compared with the experimental data.