2023-06-08 ミネソタ大学
◆通常、材料の熱伝導率は一定だが、彼らはランタン酸ストロンチウムコバルタイトで値を制御する方法を見つけた。これにより熱の流れをオンとオフできる。研究は低電力で連続的に調整可能な熱伝導率を示し、デバイスへの応用が期待される。
＜関連情報＞
- https://cse.umn.edu/college/news/researchers-tune-thermal-conductivity-materials-fly-more-energy-efficient-devices
- https://www.nature.com/articles/s41467-023-38312-z
室温イオンゲルゲーティングによるLa0.5Sr0.5CoO3-δ膜の熱伝導率の広範な連続調整 Wide-range continuous tuning of the thermal conductivity of La0.5Sr0.5CoO3-δ films via room-temperature ion-gel gating
Yingying Zhang,William M. Postiglione,Rui Xie,Chi Zhang,Hao Zhou,Vipul Chaturvedi,Kei Heltemes,Hua Zhou,Tianli Feng,Chris Leighton & Xiaojia Wang
Nature Communications Published:06 May 2023
DOI:https://doi.org/10.1038/s41467-023-38312-z
Abstract
Solid-state control of the thermal conductivity of materials is of exceptional interest for novel devices such as thermal diodes and switches. Here, we demonstrate the ability to continuously tune the thermal conductivity of nanoscale films of La0.5Sr0.5CoO3-δ (LSCO) by a factor of over 5, via a room-temperature electrolyte-gate-induced non-volatile topotactic phase transformation from perovskite (with δ ≈ 0.1) to an oxygen-vacancy-ordered brownmillerite phase (with δ = 0.5), accompanied by a metal-insulator transition. Combining time-domain thermoreflectance and electronic transport measurements, model analyses based on molecular dynamics and Boltzmann transport equation, and structural characterization by X-ray diffraction, we uncover and deconvolve the effects of these transitions on heat carriers, including electrons and lattice vibrations. The wide-range continuous tunability of LSCO thermal conductivity enabled by low-voltage (below 4 V) room-temperature electrolyte gating opens the door to non-volatile dynamic control of thermal transport in perovskite-based functional materials, for thermal regulation and management in device applications.
