Twofold rattling mode-induced ultralow thermal conductivity in vacancy-ordered double perovskite Cs<sub>2</sub>SnI<sub>6</sub>
Un-Gi Jong, Yun-Sim Kim, Chol-Hyok Ri, Yun-Hyok Kye, Chol-Jin Pak, Stefaan Cottenier, Chol‐Jun Yu
Abstract
with only Cs atom rattlers, largely scatter heat-carrying acoustic phonons strongly coupled with low-lying optical phonons and lower phonon group velocity. Using renormalized phonon dispersions at finite temperatures, we reveal that anharmonicity and twofold rattling modes induce an ultralow thermal conductivity at room temperature.
Topics & Concepts
AnharmonicityPhononThermal conductivityVacancy defectCondensed matter physicsMaterials scienceAtom (system on chip)Lattice (music)ThermalPhysicsThermodynamicsEmbedded systemAcousticsComputer scienceComposite materialPerovskite Materials and ApplicationsThermal Expansion and Ionic ConductivityAdvanced Thermoelectric Materials and Devices