Predicting thermal conductivity of materials with high precision and at large scale

Orateur : Wu LI

The thermal conductivity (ê) is a crucial property of materials in many applications such as thermoelectric, heat management and non-volatile memories. In addition, the knowledge of ê of materials under extreme conditions can help understand the mineral constitution of the earth mantle. On the other hand, parameter-free calculations in materials science are becoming more and more important when searching for new materials with desired functionalities. In this talk, I will explain how we study materials thermal conductivity by using Boltzmann’s transport equation without any adjustable parameters. I will then illustrate this with specific examples of some systems such as SixGe1-x and Mg2SixSn1-x, which are of particular interest to thermoelectric applications. Special emphasis on the reduction of ê in nanostructures will be made, which is key to the improvement of energy conversion efficiency of the thermoelectric materials. Finally, I will present our results for several hundreds of half-Heusler materials, an example of high-throughput (large scale) study, which is an emerging trend in materials science. References [1] S. Curtarolo, G. L. W. Hart, M. Buongiorno Nardelli, N. Mingo, S. Sanvito, and O. Levy, The highthroughput highway to computational materials design, Nature Materials, 12, 191(2013). [2] W. Li, N. Mingo, L. Lindsay, D. A. Broido, D. A. Stewart, and N. A. Katcho, Thermal conductivity of diamond nanowires from first principles, Phys. Rev. B 85, 195436 (2012). [3] W. Li, L. Lindsay, D. A. Broido, D. A. Stewart, and N. Mingo, Thermal conductivity of bulk and nanowire Mg2SixSn1-x alloys from first principles, Phys. Rev. B 86, 174307 (2012). [4] J. Carrete, W. Li, and N. Mingo, S. Wang and S. Curtarolo, Finding unprecedentedly low thermal conductivity half-Heusler compounds via high-throughput materials modeling, submitted.

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