Pressure effects on structure, mechanical properties and thermal conductivity of V₂SnC: a first-principles study

ABSTRACT

Recently, a new layered-ternary compound V₂SnC was successfully synthesised by reacting V, Sn, and C powder mixture at 1000°C. Its space group was identified as P6₃/mmc. In this work, the structural, mechanical properties, and thermal conductivity of this new layered-ternary compound have been studied under pressure up to 100 GPa by density functional theory. The calculated lattice parameters and cell volume of V₂SnC at the ground state are in good coincidence with the experimental values. With the increase of pressure, the a-axis of V₂SnC crystal structure has greater compressibility than the c-axis. In addition, the calculated results of elastic constants and phonon dispersion curves indicated that V₂SnC is mechanically and dynamically stable from 0 to 100 GPa. Furthermore, the influence of pressure on bulk modulus B, shear modulus G, aggregate acoustic velocities v_m, Debye temperature Θ_D, Poisson’s ratio σ, and Grüneisen parameter γ are systematically investigated. Meanwhile, the elastic anisotropy of V₂SnC under external pressure is also studied for the first time. Finally, the minimum thermal conductivity of V₂SnC under external pressure is further studied. The results show that this material has good thermal insulation performance.

KEYWORDS:

• Density functional theory
• mechanical properties
• thermal conductivity
• V₂SnC

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China under grant numbers 11904282, 11805151, and 12005166, the Doctoral Scientific Research Foundation of Xi’an University of Science and Technology under grant number 2018QDJ029, and the Natural Science Foundation of Shaanxi Provincial Department of Education under grant number 20JK0764.