“The textbook said we should see slow, gradual and random. But what we saw? BOOM! Fast, explosive and organized!” said Michael Tringides, physicist at the U.S. Department of Energy’s Ames Laboratory and a professor of physics and astronomy at Iowa State University.
Tringides is talking about the unusual atom movement he saw when they dropped a few thousand lead atoms onto a flat, smooth lead-on-silicon surface, all at low temperatures, and looked at an area just one-twentieth the width of a human hair.
What the Ames Laboratory scientists expected to see was “random-walk diffusion”: atoms milling around, looking like they have no idea where they’re going, where they’ve been, or that any fellow atoms are near them. Typically, the atoms eventually happen to run into each other and create small structures.
“Instead, we saw atoms that are very focused and work together well to quickly create tiny lead nanostructures,” said Tringides. “That kind of ‘collective diffusion,’ is really the exception to the rule in atom movement. Plus, we were surprised by how fast well-organized crystal structures nucleate at such cold temperatures, where movement is typically slow.”
The collective, fast diffusion observed by Tringides’ team could represent a new way to grow perfect, tiny metal nanostructures.
“If we’re able to make a nanoscale lead object this fast, we can perhaps create other objects this way.” said Tringides. “Understanding the basic science of how materials work at these nanoscales may be key to making nanotransistors, nanoswitches and nanomagnets smaller, faster and reliably.”
Tringides’ research team specializes in measuring how atoms move on surfaces, revealing through scanning tunneling microscopy how the smallest structures begin to form. Over the past several years, they’ve used their expertise to answer fundamental questions about materials, such as rare-earths, graphene and metallic films, that are important to green energy technologies.
This research, which appeared in Physical Review Letters, is supported by the U.S. Department of Energy Office of Science.
Ames Laboratory is a U.S. Department of Energy Office of Science national laboratory operated by Iowa State University. Ames Laboratory creates innovative materials, technologies and energy solutions. We use our expertise, unique capabilities and interdisciplinary collaborations to solve global problems.
DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov
Breehan Gerleman Lucchesi
Breehan Gerleman Lucchesi | newswise
20.02.2017 | Arizona State University
Using a simple, scalable method, a material that can be used as a sensor is developed
15.02.2017 | University of the Basque Country
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
21.02.2017 | Earth Sciences
21.02.2017 | Medical Engineering
21.02.2017 | Trade Fair News