Chen Shih-Hsun, Wang Chiu-Yen, Chen Lih-Juann, Liu Tzeng-Feng, Chaol Chuen-Guang
Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 30050, Taiwan.
J Nanosci Nanotechnol. 2010 Oct;10(10):6324-31. doi: 10.1166/jnn.2010.2629.
The size effects on solidification and the formation mechanism of the segmented eutectic Bi-43Sn nanowires during in situ annealing have been investigated. A directional solidification along the wire axis limits the segmented eutectic nanowire to arrange axially during the in situ annealing processes due to directional solidification. In 70 nm nanowires, the small size confines the convection in liquid, which results in differences in the microstructure and composition profiles between 70 and 200 nm nanowires. In the vacuum hydraulic pressure injection process, the directional cooling helps the formation of single crystal, and the isotropic solidification leads to polycrystalline microstructure.
研究了尺寸对凝固的影响以及原位退火过程中分段共晶Bi-43Sn纳米线的形成机制。由于定向凝固，沿线轴的定向凝固限制了分段共晶纳米线在原位退火过程中沿轴向排列。在70nm的纳米线中，小尺寸限制了液体中的对流，这导致了70nm和200nm纳米线在微观结构和成分分布上的差异。在真空液压注射过程中，定向冷却有助于单晶的形成，而各向同性凝固则导致多晶微观结构。
