Argonne, ILLFor the first time scientists have been able to watch nanoparticles grow from the earliest stages of their formation. Nanoparticles are the foundation of nanotechnology and their performance depends on their structure, composition, and size. Researchers will now be able to develop ways to control conditions under which they are grown. The breakthrough will affect a wide range of applications including solar-cell technology and chemical and biological sensors. The research is published in NANOLetters.
As coauthor Wenge Yang of the Carnegie Institution's Geophysical Laboratory explained: "It's been very difficult to watch these tiny particles be born and grow in the past because traditional techniques require that the sample be in a vacuum and many nanoparticles are grown in a metal-conducting liquid. So we have not been able to see how different conditions affect the particles, much less understand how we can tweak the conditions to get a desired effect."
These researchers work at the Center for Nanoscale Materials and the Advanced Photon Source (APS)both operated by Argonne National Laboratoryand the High Pressure Synergetic Consortium (HPSynC), a program jointly run by the Geophysical Laboratory and Argonne. The scientists used high-energy X-rays from the APS to carry out diffraction studies that enabled them to gain information on the crystal structure of the materials. Thanks to the highly brilliant and high penetration of this X-ray sourcethe largest of its kind in the USthe researchers were able to watch the crystals grow from the beginning of their lives. The atoms scatter very short wavelength X-rays and the resulting diffraction pattern reveals the structure of these unusual particles. Quite often the chemical reaction occurs in a very short time and then evolves. The scientists used highly focused high-energy X-rays and a fast area detector, the key components to make this investigation possible. This is the first
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