First-Principles Analysis of Lattice Thermal Conductivity in Monolayer Mn₂C

The thermal transport properties of a new MXene material, Mn₂C, have been investigated by solving the phonon Boltzmann transport equation based on the density functional theory. Monolayer Mn₂C shows a relatively low intrinsic lattice thermal conductivity, which is about one-third that of Ti₂C at room temperature. This is mainly due to the larger average atomic mass and stronger anharmonicity of Mn₂C, which result from the larger difference in electronegativity between Mn and C atoms. Moreover, the greater participation of optical branches in phonon scattering also contributes to the lower lattice thermal conductivity of monolayer Mn₂C. This study offers physical insights into the fundamental thermal transport properties of late-transition-metal-based (groups after VIB) MXene materials relevant for energy conversion and storage applications.