Tabata Koudai, Seki Takehito, Findlay Scott D, Ishikawa Ryo, Tamura Ryuji, Ikuhara Yuichi, Shibata Naoya
Institute of Engineering Innovation School of Engineering The University of Tokyo 2-11-16 Yayoi Bunkyo Tokyo 113-8656 Japan.
PRESTO Japan Science and Technology Agency 4-1-8 Honcho Kawaguchi Saitama 332-0012 Japan.
Small Sci. 2024 Feb 17;4(4):2300254. doi: 10.1002/smsc.202300254. eCollection 2024 Apr.
Controlling nanoscale heat generation, dissipation, and transport is crucial for miniaturizing electronic devices and for designing highly efficient thermoelectric materials. However, it has been challenging to directly measure thermal properties at individual atom level. Herein, direct atomic-resolution column-by-column imaging of the rattling motion of Ba atoms in a clathrate compound BaGaGe using atomic-resolution scanning transmission electron microscopy with a segmented detector is shown. The directional anisotropy of the rattling motion is clearly visualized in real space and its amplitude and anisotropy are quantitatively evaluated by Bayesian analysis of the thermal diffuse scattering distribution. These results open a new possibility for directly characterizing nanoscale thermal properties in materials and devices, even those containing heavy elements such as thermoelectric materials.
控制纳米级的热产生、耗散和传输对于电子设备的小型化以及设计高效的热电材料至关重要。然而，在单个原子水平上直接测量热性质一直具有挑战性。在此，展示了使用带有分段探测器的原子分辨率扫描透射电子显微镜对包合物BaGaGe中Ba原子的晃动运动进行逐列直接原子分辨率成像。晃动运动的方向各向异性在实空间中清晰可见，并且通过对热漫散射分布的贝叶斯分析对其振幅和各向异性进行了定量评估。这些结果为直接表征材料和器件中的纳米级热性质开辟了新的可能性，甚至对于包含热电材料等重元素的材料和器件也是如此。
