A genomic approach to the stability, elastic, and electronic properties of the MAX phases

• Published in: Physica Status Solidi. B: Basic Solid State Physics Vol. 251; no. 8; pp. 1480 - 1497
• Main Authors: Aryal, Sitaram, Sakidja, Ridwan, Barsoum, Michel W., Ching, Wai-Yim
• Format: Journal Article
• Language: English
• Published: Blackwell Publishing Ltd 01-08-2014
• Subjects: Crystals; Density; Elastic constants; elastic properties; Electronic properties; Electronic structure; genomic approaches; MAX phases; Phases; Stability
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.201451226

In this study, we report a comprehensive assessment on the elastic and electronic properties of 792 possible MAX (Mn+1AXn) phases with n = 1–4 using ab initio methods. These crystals are then screened based on their elastic and thermodynamic stability resulting in a large database of 665 viable crystals. All the experimentally verified MAX phases passed the screening. Various correlations among and between them are fully explored. In particular, the key elements in the interdependence between the elastic properties together with mechanical parameter derived from them and the electronic structure are identified. Detailed analysis of various correlation plots shows that there is a clear correspondence between bulk modulus K and total bond order density (TBOD). Calculations show a marked difference between the carbides and nitrides. This database is also used to test the efficacy of data mining algorithms for materials genome. We further identified several thermodynamically stable new MAX phases with unusual mechanical parameters that have never been synthesized in the laboratory or theoretically investigated. The complete database on the elastic and electronic structure together with the mechanical parameters for these 665 MAX phases compounds are included in the Supplementary Materials and fully accessible.