Thermodynamic Modeling of the Al-Ba and Ba-Ge Systems Supported by First-Principles Calculations

• Published in: Journal of phase equilibria and diffusion 2019-04, Vol.40 (2), p.195-205
• Main Authors: Benhafid, R., Belgacem Bouzida, A., Djaballah, Y., Candan, A., İyigör, A., Uğur, G.
• Format: Article
• Language: English
• Subjects: Ceramics; Composites; Computer simulation; Coupling (molecular); Crystallography and Scattering Methods; Density functional theory; Engineering Thermodynamics; First principles; Glass; Heat and Mass Transfer; Intermetallic compounds; Metallic Materials; Natural Materials; Phase diagrams; Phase transitions; Physics; Physics and Astronomy; Polynomials; Thermodynamic models; Thermodynamic properties; Thermodynamics
• ISSN: 1547-7037; 1863-7345; 1934-7243
• DOI: 10.1007/s11669-019-00714-2

The phase diagrams of Al-Ba and Ba-Ge systems are optimized by coupling the CALPHAD approach and first-principles calculations. The binary intermetallic compounds were treated as stoichiometric phases. The total energies of nine intermetallic compounds: Al 4 Ba, Al 13 Ba 7 , Al 5 Ba 3 , Al 5 Ba 4 , Ba 2 Ge, Ba 5 Ge 3 , BaGe, β-Ba 3 Ge 4 and BaGe 2 were calculated by first-principles calculation using density functional theory approximation as implemented in the VASP (Vienna Ab-initio Simulation Package) code and used in the CALPHAD approach to assess the two systems. The liquid solutions are described by the Redlich–Kister polynomial model. A set of thermodynamic parameters were obtained for the Al-Ba and Ba-Ge systems. The calculated phase diagrams and thermodynamic properties are in good agreement with most of the accuracy available data.