Positive temperature coefficient of the thermal conductivity above room temperature in a perovskite cobaltite.

ABSTRACT: The thermal conductivity above room temperature is investigated for LaCoO₃-based materials showing spin-state and insulator-metal crossovers. A positive temperature coefficient (PTC) of the thermal conductivity is observed during the insulator-metal crossover around 500 K. Our analysis indicates that the phononic thermal transport is also enhanced in addition to the electronic contribution as the insulator-metal crossover takes place. The enhancement of the phononic component is ascribed to the reduction of the incoherent local lattice distortion coupled with the spin/orbital state of each Co³⁺ ion, which is induced by the enhanced spin-state fluctuation between low and excited spin-states. Moreover, fine tunability for the PTC of the thermal conductivity is demonstra

SUBMITTER: Doi A 

PROVIDER: S-EPMC9744203 | biostudies-literature | 2022

REPOSITORIES: biostudies-literature