{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"omics_type":["Unknown"],"volume":["23(1)"],"submitter":["Doi A"],"pubmed_abstract":["The thermal conductivity above room temperature is investigated for LaCoO<sub>3</sub>-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 Co<sup>3+</sup> 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 demonstrated via doping hole-type carriers into LaCoO<sub>3</sub>. The observed enhancement ratio of the thermal conductivity <i>κ</i> <sub>T</sub> (773 K) / <i>κ</i> <sub>T</sub> (323 K) = 2.6 in La<sub>0.95</sub>Sr<sub>0.05</sub>CoO<sub>3</sub> is the largest value among oxide materials which exhibit a PTC of their thermal conductivity above room temperature. The thermal rectification ratio is estimated to reach 61% for a hypothetical thermal diode consisting of La<sub>0.95</sub>Sr<sub>0.05</sub>CoO<sub>3</sub> and LaGaO<sub>3</sub>, the latter of which is a typical band insulator. These results indicate that utilizing spin-state and orbital degrees of freedom in strongly correlated materials is a useful strategy for tuning thermal transport properties, especially for designing thermal diodes."],"journal":["Science and technology of advanced materials"],"pagination":["858-865"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC9744203"],"repository":["biostudies-literature"],"pubmed_title":["Positive temperature coefficient of the thermal conductivity above room temperature in a perovskite cobaltite."],"pmcid":["PMC9744203"],"pubmed_authors":["Taguchi Y","Kriener M","Kikkawa A","Doi A","Shimano S","Tokura Y"],"additional_accession":[]},"is_claimable":false,"name":"Positive temperature coefficient of the thermal conductivity above room temperature in a perovskite cobaltite.","description":"The thermal conductivity above room temperature is investigated for LaCoO<sub>3</sub>-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 Co<sup>3+</sup> 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 demonstrated via doping hole-type carriers into LaCoO<sub>3</sub>. The observed enhancement ratio of the thermal conductivity <i>κ</i> <sub>T</sub> (773 K) / <i>κ</i> <sub>T</sub> (323 K) = 2.6 in La<sub>0.95</sub>Sr<sub>0.05</sub>CoO<sub>3</sub> is the largest value among oxide materials which exhibit a PTC of their thermal conductivity above room temperature. The thermal rectification ratio is estimated to reach 61% for a hypothetical thermal diode consisting of La<sub>0.95</sub>Sr<sub>0.05</sub>CoO<sub>3</sub> and LaGaO<sub>3</sub>, the latter of which is a typical band insulator. These results indicate that utilizing spin-state and orbital degrees of freedom in strongly correlated materials is a useful strategy for tuning thermal transport properties, especially for designing thermal diodes.","dates":{"release":"2022-01-01T00:00:00Z","publication":"2022","modification":"2025-04-18T16:31:46.813Z","creation":"2025-04-07T03:48:21.6Z"},"accession":"S-EPMC9744203","cross_references":{"pubmed":["36518983"],"doi":["10.1080/14686996.2022.2149035"]}}