AI Article Synopsis
- Low-dimensional materials can exhibit unusual thermal conduction where thermal conductivity increases with length, a phenomenon not seen in bulk materials.
- Previous studies faced challenges due to finite-size effects, leading to inconclusive results.
- This research shows that single-wall carbon nanotubes have a thermal conductivity that continues to grow over lengths exceeding 1 mm, reaching 8640 W/mK at room temperature, even in the presence of defects, indicating new possibilities for heat manipulation in materials.
Article Abstract
Low-dimensional materials could display anomalous thermal conduction that the thermal conductivity (κ) diverges with increasing lengths, in ways inconceivable in any bulk materials. However, previous theoretical or experimental investigations were plagued with many finite-size effects, rendering the results either indirect or inconclusive. Indeed, investigations on the anomalous thermal conduction must demand the sample length to be sufficiently long so that the phenomena could emerge from unwanted finite-size effects. Here we report experimental observations that the κ's of single-wall carbon nanotubes continuously increase with their lengths over 1 mm, reaching at least 8640 W/mK at room temperature. Remarkably, the anomalous thermal conduction persists even with the presence of defects, isotopic disorders, impurities, and surface absorbates. Thus, we demonstrate that the anomalous thermal conduction in real materials can persist over much longer distances than previously thought. The finding would open new regimes for wave engineering of heat as well as manipulating phonons at macroscopic scales.
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| http://dx.doi.org/10.1103/PhysRevLett.118.135901 | DOI Listing |
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