DFT insights into the electronic structure, mechanical behaviour, lattice dynamics and defect processes in the first Sc-based MAX phase Sc2SnC

M A Hadi; S-R G Christopoulos; A Chroneos; S H Naqib; A K M A Islam

doi:10.1038/s41598-022-18336-z

DFT insights into the electronic structure, mechanical behaviour, lattice dynamics and defect processes in the first Sc-based MAX phase Sc₂SnC

Sci Rep. 2022 Aug 18;12(1):14037. doi: 10.1038/s41598-022-18336-z.

Authors

M A Hadi¹, S-R G Christopoulos², A Chroneos^{3

4}, S H Naqib⁵, A K M A Islam^{5

6}

Affiliations

¹ Department of Physics, University of Rajshahi, Rajshahi, 6205, Bangladesh. hadipab@gmail.com.
² Faculty of Engineering, Environment and Computing, Coventry University, Priory Street, Coventry, CV1 5FB, UK.
³ Department of Electrical and Computer Engineering, University of Thessaly, 38221, Volos, Greece.
⁴ Department of Materials, Imperial College, London, SW7 2AZ, UK.
⁵ Department of Physics, University of Rajshahi, Rajshahi, 6205, Bangladesh.
⁶ International Islamic University Chittagong, Kumira, Chittagong, 4318, Bangladesh.

Abstract

Here we employed the density functional theory calculations to investigate some physical properties of first Sc-based MAX phase Sc₂SnC including defect processes to compare with those of existing M₂SnC phases. The calculated structural properties are in good agreement with the experimental values. The new phase Sc₂SnC is structurally, mechanically and dynamically stable. Sc₂SnC is metallic with a mixture of covalent and ionic character. The covalency of Sc₂SnC including M₂SnC is mostly controlled by the effective valence. Sc₂SnC in M₂SnC family ranks second in the scale of deformability and softness. The elastic anisotropy level in Sc₂SnC is moderate compared to the other M₂SnC phases. The hardness and melting point of Sc₂SnC, including M₂SnC, follows the trend of bulk modulus. Like other members of the M₂SnC family, Sc₂SnC has the potential to be etched into 2D MXenes and has the potential to be a thermal barrier coating material.