Accurate Prediction of the Thermal Conductivity for All Classes of Materials
|Figure 1: Non-perturbative, ab initio calculations (density-functional theory) that reproduce and explain the thermal conductivity of silicon (heat conductor) and zirconia (ZrO2, heat insulator). Adopted from C. Carbogno, R. Ramprasad, and M. Scheffler, Phys. Rev. Lett. 118, 175901 (2017).|
Experimental knowledge about the heat conductivity of solid materials is rare, but critically needed for many industrial and scientific applications, ranging from semiconductor technology to aircraft turbine engineering. For instance, zirconia-based thermal barrier coatings have driven the fuel-efficiency improvement in turbines over the last 30 years. From the theory side, an accurate and predictive assessment for the whole range of possible materials had hitherto remained elusive. At elevated temperatures, for instance, the interactions and dynamics of the atoms becomes so intricate that it can no longer be described by approximate, perturbative approaches – as employed in existing heat transport calculations, so far.
In a recently published Physical Review Letter, Christian Carbogno, Rampi Ramprasad, and Matthias Scheffler derive a novel, accurate, and efficient first-principles description of heat transport in solid materials. This includes an extrapolation procedure that enables the ab initio description of phonon mean free paths that can occur in all classes of realistic materials: from the nano- to the micro-meter scale. They demonstrate the applicability of the approach by computing heat transport of extreme cases in terms of high and low heat conducting materials, namely silicon and zirconia. For details see:
With this technique, we are now in the position to start systematic and accurate high-throughput calculations
of the thermal conductivity tensor for all kind of materials.