Realization of diversity in physical properties of Zr2Se(B1‐xSex) MAX phases through DFT approach

• Published in: Journal of the American Ceramic Society 2023-10, Vol.106 (10), p.6177-6193
• Main Authors: Hadi, Mohammad A., Akhter, Mehnaj, Ahasan, Mohammad Shamim, Ahmed, Istiak, Kashem, Mohammad A.
• Format: Article
• Language: English
• Subjects: Composition; Debye temperature; Density functional theory; Diamond pyramid hardness; Dynamic stability; Elastic properties; Heat conductivity; Heat transfer; MAX phases; Physical properties; Thermal barrier coatings; Thermal conductivity
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.19271

The discovery of a series of MAX phases, Zr2Se(B1‐xSex), with Se at both A‐ and X‐sites, drives a new chemical diversity to the MAX family. Here, we employed the density functional theory (DFT) approach to realize the diversity in physical properties of Zr2Se(B1‐xSex). All compositions of Zr2Se(B1‐xSex) are mechanically stable and the dynamical stability of the end member Zr2SeSe is confirmed. The elastic constant C33 and bulk moduli B show a decrease almost monotonically with Se‐content x while other constants and moduli change irregularly. All elastic constants and moduli except C12 and C13 are highest for the end member Zr2SeB. Additionally, the Vickers hardness, Debye temperature, minimum thermal conductivity, and lattice thermal conductivity are highest for Zr2SeB. The increase of Se‐content x at X‐site reduces most of the properties of Zr2Se(B1‐xSex). The electronic band structures change drastically with increasing Se‐content x. This diversity in electronic band structures is mainly the reason for the diversity in physical properties of Zr2Se(B1‐xSex). All compositions of Zr2Se(B1‐xSex) have the potential to be thermal barrier coating materials, and Zr2SeB has the potential to be etched into 2D MXene, Zr2B.