Unusual thermo-mechanical properties of the Janus Mo2ScC2OH MXene monolayer

Abstract

In this study, we investigated the structural, electronic, mechanical, dynamical, and thermal properties of the Janus Mo₂ScC₂OH MXene monolayer using ab initio calculations based on density functional theory. The results showed that Janus Mo₂ScC₂OH is metallic and mechanically stable. We found that Mo₂ScC₂OH has high Poisson's ratio. Phonon dispersion calculations revealed that there are no imaginary frequencies, suggesting that the Janus Mo₂ScC₂OH monolayer is dynamically stable. Debye temperature, Grüneisen parameters, thermodynamic properties, and lattice thermal conductivity have also been calculated. The results revealed that Mo₂ScC₂OH has high negative Grüneisen parameters, indicating that it could be a negative thermal expansion material. Additionally, we noted that the Janus Mo₂ScC₂OH monolayer exhibits a relatively low lattice thermal conductivity, with a notable contribution from the ZA mode.