Hexagonal Close-Packed Structure of Au Nanocatalysts Solidified after Ge Nanowire Vapor−Liquid−Solid Growth

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• 作者：Ann F. Marshall ; Irene A. Goldthorpe ; Hemant Adhikari ; Makoto Koto ; Young-Chung Wang ; Lianfeng Fu ; Eva Olsson ; Paul C. McIntyre
• 刊名：Nano Letters
• 出版年：2010
• 出版时间：September 8, 2010
• 年：2010
• 卷：10
• 期：9
• 页码：3302-3306
• 全文大小：305K
• 年卷期：v.10,no.9(September 8, 2010)
• ISSN：1530-6992

文摘

We report that approximately 10% of the Au catalysts that crystallize at the tips of Ge nanowires following growth have the close-packed hexagonal crystal structure rather than the equilibrium face-centered-cubic structure. Transmission electron microscopy results using aberration-corrected imaging, and diffraction and compositional analyses, confirm the hexagonal phase in these 40−50 nm particles. Reports of hexagonal close packing in Au, even in nanoparticle form, are rare, and the observations suggest metastable pathways for the crystallization process. These results bring new considerations to the stabilization of the liquid eutectic alloy at low temperatures that allows for vapor−liquid−solid growth of high quality, epitaxial Ge nanowires below the eutectic temperature.

Keywords:

Hexagonal close-packed Au; Ge nanowires; Au catalyst; subeutectic vapor−liquid−solid growth; aberration-corrected transmission electron microscopy