Effects of magnetic ordering on structural stability and phonon transport in monolayer Td-VX2 (X=Se, I)

The effects of magnetic ordering on phonon transport and structural stability of monolayer Td-VX2 (X=Se, I) are systematically investigated by the first-principles calculations with phonon Boltzmann transport equation. For monolayer Td-VI2, magnetic ordering can stabilize its lattice structure since the imaginary frequency appearances once the magnetic ordering is ignored. The magnetic ordering effect is further displayed from the phonon transport in monolayer Td-VSe2. We find that the lattice thermal conductivity of Td-VSe2 jumps from 3.41 to 4.79 W/m-K at Curie temperature of 320 K, which originates from magnetic ordering induced enhancement of phonon group velocity and lifetime.