Hexagonal close-packed structure of Au nanocatalysts solidified after Ge nanowire vapor-liquid-solid growth

• 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.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

Nyckelord

Au catalyst

aberration-corrected transmission electron microscopy

Hexagonal close-packed Au

subeutectic vapor-liquid-solid growth

Ge nanowires

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