An interpretable formula for lattice thermal conductivity of crystals

Abstract

Lattice thermal conductivity (κ_L) is a crucial physical property of crystals with applications in thermal management, such as heat dissipation, insulation, and thermoelectric energy conversion. However, accurately and rapidly determining κ_L poses a considerable challenge. In this study, we introduce a formula that achieves high precision (mean relative error = 8.97 %) and provides fast predictions, taking less than 1 min, for κ_L across a wide range of inorganic binary and ternary materials. Our interpretable, dimensionally aligned and physical grounded formula forecasts κ_L values for 4601 binary and 6995 ternary materials in the Materials Project database. Notably, we predict undiscovered high κ_L values for AlBN₂ (κ_L = 101 W m⁻¹ K⁻¹) and the undetected low κ_L Cs₂Se (κ_L = 0.98 W m⁻¹ K⁻¹) at room temperature. This method for determining κ_L streamlines the traditionally time-consuming process associated with complex phonon physics. It provides insights into microscopic heat transport and facilitates the design and screening of materials with targeted and extreme κ_L values through the application of phonon engineering. Our findings offer opportunities for controlling and optimizing macroscopic transport properties of materials by engineering their bulk modulus, shear modulus, and Grüneisen parameter.