Phonon engineering through crystal chemistry

TLDR

Tailoring thermal conductivity is essential to mitigate the global energy crisis, and low thermal conductivity is critical for technologies such as thermoelectrics and thermal barrier coatings, prompting strategies to combine mechanisms for designing new materials with exceptionally low thermal conductivity. The review aims to examine chemical trends and origins of low thermal conductivity in crystalline materials. The authors analyze chemical trends and investigate mechanisms that reduce thermal conductivity in crystalline materials. A unifying feature in the latest materials is the incorporation of structural complexity to decrease phonon velocity and increase scattering.

Abstract

Mitigation of the global energy crisis requires tailoring the thermal conductivity of materials. Low thermal conductivity is critical in a broad range of energy conversion technologies, including thermoelectrics and thermal barrier coatings. Here, we review the chemical trends and explore the origins of low thermal conductivity in crystalline materials. A unifying feature in the latest materials is the incorporation of structural complexity to decrease the phonon velocity and increase scattering. With this understanding, strategies for combining these mechanisms can be formulated for designing new materials with exceptionally low thermal conductivity.