First-principles phonon calculations for lattice dynamics, thermal expansion and lattice thermal conductivity of CoSi in the high temperature region

Abstract This study presents the first-principles phonon calculations to understand experimental thermal expansion ( ) and lattice conductivity $(\kappa_{L})$ of CoSi in high temperature region. Phonon dispersion is computed using finite displacement method supercell approach by taking equilibrium crystal structures obtained from DFT. The calculation done under quasi-harmonic approximation. $\kappa_{L}$ calculated first-principle anharmonic dynamics single-mode relaxation time range 0–1300 K gives a good match with existing data. value (∼8.0 W/mK) at 300 found be agreement ∼8.3 W/mK. dependence lifetime due phonon-phonon interaction behaviour . present suggests that ground state DFT-based methods reasonably explanation