Electronic and lattice thermal conductivity switching by 3D−2D crystal structure transition in nonequilibrium (Pb$_{1−x}$Sn$_x$)Se

Abstract

Abstract Dynamic control of thermal transport in solid materials is highly desired for thermal management technology. However, the development of a material exhibiting large modulation of thermal conductivity (?) by external stimuli remains a major challenge. Here, the large ? modulation is reported by the reversible 3D to 2D crystal structure transition in a nonequilibrium solid solution of (Pb1?xSnx)Se, where Pb2+ stabilizes a 3D cubic structure while Sn2+ does a 2D layered structure. The phase boundary of these phases is induced in (Pb0.5Sn0.5)Se bulk polycrystals by thermally quenching the high-temperature solid solution phase. Through the 3D?2D phase transition, the 1/2.9-times decrease of lattice ? (?lat.) is achieved by strong phonon scattering in the 2D layered structure, and the electronic ? (?ele.) is also decreased by 5 orders of magnitude due to the electronic phase transition from a 3D high conductivity state to a 2D semiconducting state. The total ? (=?lat. + ?ele.) modulation ratio ?3D phase/?2D phase = 3.6 is attained at 373 K. The present strategy will lead to a novel concept for designing thermal management materials through crystal-structure dimensionality switch using nonequilibrium phase boundaries.

Terumasa Tadano

Researcher of Materials Science

My research interests include development of computational methods and softwares for predicting thermal properties of solids, and application of machine-learning methods to material science study