Controlled fabrication of gold nanotip arrays by nanomolding-necking technology

Abstract

The fabrication of nanotips has been driven by the increasing industrial demands in developing high-performance multifunctional nanodevices. In this work, we proposed a controlled, rapid as well as low cost nanomolding-necking technology to fabricate gold nanotips arrays. The geometries of gold nanotips having cone angle range of ∼28–77° and curvature radii of <5 nm can be prepared by tailoring the diameters of raw nanorods in nanomolding process or modulating the necking temperature. Molecular dynamics simulation reveals that the formation of the nanotip geometry is determined by the interplay between dislocation-based and diffusion-based deformation mechanisms, intrinsically arising from the nonlinear dependence of atom diffusion on temperature and sample size. The good controllability, mass production and low cost of the developed nanomolding-necking technology make it highly promising in developing nanodevices for a wide range of applications, such as probing, sensing, antireflection coating and nanoindentation.

Transport and coarsening of gold nanoparticles in an orogenic deposit by dissolution–reprecipitation and Ostwald ripening

“…The underlying mechanism for gold coarsening may, however, differ between orogenic (attachment, dissolution, and monomer transfer) and epithermal (diffusion-limited aggregation and orthokinetic aggregation) 8 deposits. The existence of these different gold coarsening processes has far-reaching implications for other disciplines given that gold nanoparticle research is a critical component of material science 40,41 , nanomedicine 42,43 , and nanotechnology 44,45 . A more complete understanding of natural gold nanoparticles and their interaction with other natural materials may enhance laboratory manipulation for a variety of disciplines.…”