Strong crystalline thermal insulation induced by extended antibonding states.

ABSTRACT: Crystalline solids with extreme insulation often exhibit a plateau or even an upward-sloping tail in thermal conductivity above room temperature. Herein, we synthesize a crystalline material AgTl₂I₃ with an exceptionally low thermal conductivity of 0.21 Wm^-1K^-1 at 300 K, which continues to decrease to 0.17 Wm^-1K^-1 at 523 K. We adopt an integrated experimental and theoretical approach to reveal the lattice dynamics and thermal transport properties of AgTl₂I₃. Our results suggest that the Ag-I polyhedron enables extended antibonding states to weaken the chemical bonding, fostering strong lattice anharmonicity driven by the rattling vibrations of Ag atoms and causing lattice softening. Experimental measure

SUBMITTER: Cheng R 

PROVIDER: S-EPMC12381141 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature