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arXiv 1408.6747cond-mat.mes-hall
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利用纳米尺度膜重构声子平均自由程对热导率的贡献

Reconstructing phonon mean free path contributions to thermal conductivity using nanoscale membranes

John Cuffe, Jeffery K. Eliason, Alexei A. Maznev, Kimberlee C. Collins, Jeremy A. Johnson, Andrey Shchepetov, Mika Prunnila, Jouni Ahopelto, Clivia M. Sotomayor… 展开作者

John Cuffe, Jeffery K. Eliason, Alexei A. Maznev, Kimberlee C. Collins, Jeremy A. Johnson, Andrey Shchepetov, Mika Prunnila, Jouni Ahopelto, Clivia M. Sotomayor Torres, Gang Chen, Keith A. Nelson

摘要:

载热声子的平均自由程分布的知识是理解声子介导的热输运的关键。我们表明,跨越很宽的厚度范围内的薄膜的热导率测量可以用来表征体热导率是如何分布在声子平均自由程。采用非接触式瞬态热栅技术测量了厚度为15 ~ 1500 nm的悬浮硅膜的热导率。在此厚度范围内,观察到从74%到13%的体积值的热导率的下降,这是由于扩散声子边界散射。由于薄膜厚度与声子平均自由程抑制之间存在明确的关系,结合测量的范围和精度,我们可以重建体热导率累积与声子平均自由程的关系,并与理论模型进行比较。

英文摘要:

Knowledge of the mean free path distribution of heat-carrying phonons is key to understanding phonon-mediated thermal transport. We demonstrate that thermal conductivity measurements of thin membranes spanning a wide thickness range can be used to characterize how bulk thermal conductivity is distributed over phonon mean free paths. A non-contact transient thermal grating technique was used to measure the thermal conductivity of suspended Si membranes ranging from 15 to 1500 nm in thickness. A decrease in the thermal conductivity from 74% to 13% of the bulk value is observed over this thickness range, which is attributed to diffuse phonon boundary scattering. Due to the well-defined relation between the membrane thickness and phonon mean free path suppression, combined with the range and accuracy of the measurements, we can reconstruct the bulk thermal conductivity accumulation vs. phonon mean free path, and compare with theoretical models.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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