The Rise of 212 MAX Phase Borides: DFT Insights into the Physical Properties of Ti2PB2, Zr2PbB2, and Nb2AB2 [A = P, S] for Thermomechanical Applications

Md Ashraf Ali; Md Mukter Hossain; Md Mohi Uddin; A K M Azharul Islam; Saleh Hasan Naqib

doi:10.1021/acsomega.2c06331

The Rise of 212 MAX Phase Borides: DFT Insights into the Physical Properties of Ti₂PB₂, Zr₂PbB₂, and Nb₂AB₂ [A = P, S] for Thermomechanical Applications

ACS Omega. 2022 Dec 16;8(1):954-968. doi: 10.1021/acsomega.2c06331. eCollection 2023 Jan 10.

Authors

Md Ashraf Ali^{1

2}, Md Mukter Hossain^{1

2}, Md Mohi Uddin^{1

2}, A K M Azharul Islam^{3

4}, Saleh Hasan Naqib^{2

4}

Affiliations

¹ Department of Physics, Chittagong University of Engineering and Technology (CUET), Chattogram4349, Bangladesh.
² Advanced Computational Materials Research Laboratory (ACMRL), Department of Physics, Chittagong University of Engineering and Technology (CUET), Chattogram4349, Bangladesh.
³ Department of Electrical and Electronic Engineering, International Islamic University Chittagong, Kumira, Chattogram4318, Bangladesh.
⁴ Department of Physics, University of Rajshahi, Rajshahi6205, Bangladesh.

Abstract

In this article, ab initio calculations of unexplored Ti₂PB₂, Zr₂PbB₂, and Nb₂AB₂ [A = P, S] were performed wherein Ti₂PB₂ along with its 211 boride phase Ti₂PB was predicted for the first time. The stability was confirmed by calculating the formation energy, phonon dispersion curve, and elastic stiffness constants. The obtained elastic constants, elastic moduli, and Vickers hardness values of Ti₂PB₂, Zr₂PbB₂, and Nb₂AB₂ [A = P, S] were found to be significantly larger than those of their counterparts 211 borides and carbides. The studied compounds are brittle, like most MAX and MAB phases. The electronic band structure and density of states revealed the metallic nature of the titled borides. Several thermal parameters were explored, certifying the suitability of Ti₂PB₂, Zr₂PbB₂, and Nb₂AB₂ [A = P, S] to be used as efficient thermal barrier coating materials. The response of Ti₂PB₂, Zr₂PbB₂, and Nb₂AB₂ [A = P, S] to the incident photon was studied by computing the dielectric constant (real and imaginary parts), refractive index, absorption coefficient, photoconductivity, reflectivity, and energy loss function. In this work, we have explored the physical basis of the improved thermomechanical properties of 212 MAX phase borides compared to their existing carbide and boride counterparts.