Diewald S, Feldmann C
Institute of Inorganic Chemistry, University of Karlsruhe (TH), Karlsruhe, Germany.
Nanotechnology. 2009 Mar 25;20(12):125704. doi: 10.1088/0957-4484/20/12/125704. Epub 2009 Mar 4.
The sintering and melting of submicron-sized bismuth particles were studied in situ via scanning electron microscopy. The relevant bismuth particles were prepared via a polyol-mediated synthesis, which results in spherical and non-agglomerated particles, about 250 nm in size. The samples as well as suitable references were deposited on a heater stage assembly inside a scanning electron microscope. Both were investigated up to temperatures of 480 degrees C. Surprisingly, sample areas continuously scanned by the electron beam showed neither sintering nor melting of submicron-sized bismuth, whereas melting was observed at temperatures between 250 and 270 degrees C in non-scanned areas. This behavior was ascribed to an electron-beam-induced decomposition of organic stabilizers that adhered on the bismuth particles to form a thin layer of amorphous carbon. For experimental verification of this hypothesis, controlled carbon coating of submicron-sized bismuth particles was conducted.
通过扫描电子显微镜对亚微米级铋颗粒的烧结和熔化进行了原位研究。相关的铋颗粒通过多元醇介导的合成方法制备，该方法可得到尺寸约为250nm的球形且无团聚的颗粒。将样品以及合适的参比物沉积在扫描电子显微镜内部的加热台组件上。两者均在高达480℃的温度下进行研究。令人惊讶的是，由电子束连续扫描的样品区域未显示出亚微米级铋的烧结或熔化现象，而在未扫描区域，在250至270℃的温度下观察到了熔化现象。这种行为归因于电子束诱导附着在铋颗粒上的有机稳定剂分解，从而形成了一层非晶碳薄层。为了对该假设进行实验验证，对亚微米级铋颗粒进行了可控的碳涂层处理。
