Fabrication and characterization of eutectic gold-silicon (Au-Si) nanowires

Abstract

Hypoeutectic, eutectic and hypereutectic gold-silicon (Au-Si) alloys were synthesized using vacuum smelting. When Au and Si were smelted in a vacuum chamber near 1100 degrees C, Si-(g), Si-2(g), Si-3(g), SiO2(g), Au-(g), SiO2(s) and Au2O3(s) were formed rapidly; the quantities of Au and Si lost were estimated from thermodynamic formulas. The nano- and microstructures of the Au-Si,eutectic compound were characterized with a SEM and a TEM, which showed a discontinuous phase of Si dispersed and mounted within a matrix phase of Au. Cracks that formed about the Au-Si interface made the Au-Si eutectic brittle. From an Au-Si alloy of superior quality as a bulk material, eutectic nanowires of average diameter 60 nm were fabricated after the alloy was melted and injected into an anodic aluminum-oxide (AAO) template. (C) 2008 Elsevier B.V. All rights reserved.