Revisiting thermal transport in CuCl: First-principles calculations and machine learning force fields

Abstract

Accurate prediction of lattice thermal conductivity (${\kappa }_l$) in strongly anharmonic materials requires renormalized interatomic force constants (IFCs) and appropriate incorporation of diagonal and off-diagonal contributions and higher-order scattering. We investigate CuCl, a highly anharmonic system with a simple zincblende structure and ultralow ${\kappa }_l$. Our calculations, including IFC renormalization and four-phonon scattering, show excellent agreement with the experiment, underscoring the critical role of both effects in the accurate estimation of ${\kappa }_l$. Furthermore, the unusual pressure dependence of ${\kappa }_l$ is explored using a rigorously validated machine-learned force field, with the predicted values showing good agreement with the experimentally observed trend of monotonic decrease. This behavior is primarily driven by a significant increase in four-phonon scattering and a reduction in the group velocity of transverse acoustic modes. Overall, this study establishes a robust framework for modeling thermal transport in strongly anharmonic materials.

9 pages, 9 figures

References in corpus (10)

• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Distribution of phonon lifetime in Brillouin zone
• On-the-fly machine learning force field generation: Application to melting points
• Phonon-Phonon Interactions in Strongly Bonded Solids: Selection Rules and Higher-Order Processes
• Intrinsic localized mode and low thermal conductivity of PbSe
• Anharmonicity in Thermal Insulators: An Analysis from First Principles
• Exposing the hidden influence of selection rules on phonon-phonon scattering by pressure and temperature tuning
• Electron-induced non-monotonic pressure dependence of the lattice thermal conductivity of θ-TaN
• Mode-coupling theory of lattice dynamics for classical and quantum crystals