Letter abstract


Nature Materials 6, 363 - 366 (2007)
Published online: 15 April 2007 | doi:10.1038/nmat1894

Subject Categories: Metals and alloys | Nanoscale materials | Computation, modelling and theory

Dispensing and surface-induced crystallization of zeptolitre liquid metal-alloy drops

Peter W. Sutter & Eli A. Sutter

Top

The controlled delivery of fluids is a key process in nature and in many areas of science and technology, where pipettes or related devices are used for dispensing well-defined fluid volumes. Existing pipettes are capable of delivering fluids with attolitre (10-18 l) accuracy at best1. Studies on phase transformations of nanoscale objects would benefit from the controlled dispensing and manipulation of much smaller droplets. In contrast to nanoparticle melting whose fundamental pathway was studied extensively2, experiments on crystallization, testing classical nucleation theory3, are hindered by the influence of support interfaces. Experiments on free-standing fluid drops are extremely challenging4. Here, we demonstrate the operation of a pipette, which, observed by transmission electron microscopy, delivers a metal-alloy melt with zeptolitre (10-21 l) resolution. We use this exquisite control to produce nearly free-standing Au72Ge28 drops suspended by an atomic-scale meniscus at the pipette tip, and to image their phase transformations with near-atomic resolution. Our observations of the liquid–solid transition challenge classical nucleation theory3 by providing experimental evidence for an intrinsic crystallization pathway of nanometre-sized fluid drops that avoids nucleation in the interior, but instead proceeds via liquid-state surface faceting as a precursor to surface-induced crystallization.

Top
  1. Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA

Correspondence to: Eli A. Sutter e-mail: esutter@bnl.gov


Extra navigation

Subscribe to Nature Materials

Subscribe

Open Innovation Challenges

  • Mitigating Zinc Corrosion

    • Deadline: Aug 23 2009
    • Reward: $20,000 USD

    The Seeker is looking for novel methods to mitigate zinc corrosion/gassing in alkaline media. This ...

  • Plant Mitotic Arrest Agent & Protocol

    • Deadline: Jul 15 2009
    • Reward: $20,000 USD

    The Seeker is looking for an efficient chromosome doubling method in plants, particularly with respe...

naturejobs

  • Postdoctoral position in Neuroscience

    • Bioengineering Institute (University Miguel Hernández) and CIBER-BBN (Networking Research Center on Bioengineering, Biomaterials and Nanomedicine)
    • Elche, SPAIN
  • Director of NMR

    • New York Structural Biology Center
    • New York, New York

natureproducts


ADVERTISEMENT