Yokota Takeshi, Murayama M, Howe J M
Department of Materials Science & Engineering, University of Virginia, Charlottesville, Virginia 22904-4745, USA.
Phys Rev Lett. 2003 Dec 31;91(26 Pt 1):265504. doi: 10.1103/PhysRevLett.91.265504. Epub 2003 Dec 29.
In situ heating and electron-beam irradiation in the transmission electron microscope were performed to study melting of submicron Al-11.6 at. % Si particles supported on a C thin film. It was found that electron irradiation could be used to melt the particles, even when the hot-stage sample holder was kept at a much lower temperature ( approximately 125 degrees C) than the initial melting point of the particles. Comparison between the experimentally observed melting behavior and analytical calculations indicate that melting of the submicron Al-Si particles under electron-beam irradiation is caused by a temperature rise due to electron thermal spikes in the particles and poor thermal conduction away from the particles. These results have important implications in transmission electron microscopy studies of nanoparticles supported on thin films or poorly conducting substrates.
在透射电子显微镜中进行原位加热和电子束辐照，以研究支撑在碳薄膜上的亚微米级Al-11.6原子百分比Si颗粒的熔化情况。研究发现，即使热台样品架保持在比颗粒初始熔点低得多的温度（约125摄氏度）下，电子辐照也可用于熔化颗粒。实验观察到的熔化行为与分析计算之间的比较表明，电子束辐照下亚微米级Al-Si颗粒的熔化是由颗粒中电子热尖峰导致的温度升高以及颗粒热传导不良引起的。这些结果对薄膜或低导电衬底上支撑的纳米颗粒的透射电子显微镜研究具有重要意义。
