The ORNL research team documented the atoms' unique behavior by first trapping groups of silicon atoms, known as clusters, in a single-atom-thick sheet of carbon called graphene.
Oak Ridge National Laboratory researchers used electron microscopy to document the 'dancing' motions of silicon atoms, pictured in white, in a graphene sheet.
The silicon clusters, composed of six atoms, were pinned in place by pores in the graphene sheet, allowing the team to directly image the material with a scanning transmission electron microscope.
The "dancing" movement of the silicon atoms, seen in a video here: http://www.ornl.gov/ornlhome/video/video_files/dancing-silicons-1.mov, was caused by the energy transferred to the material from the electron beam of the team's microscope.
"It's not the first time people have seen clusters of silicon," said coauthor Juan Carlos Idrobo. "The problem is when you put an electron beam on them, you insert energy into the cluster and make the atoms move around. The difference with these results is that the change that we observed was reversible. We were able to see how the silicon cluster changes its structure back and forth by having one of its atoms 'dancing' between two different positions."
Other techniques to study clusters are indirect, says Jaekwang Lee, first author on the ORNL study. "With the conventional instrumentation used to study clusters, it is not yet possible to directly identify the three-dimensional atomic structure of the cluster," Lee said.
The ability to analyze the structure of small clusters is important for scientists because this insight can be used to precisely understand how different atomic configurations control a material's properties. Molecules could then be tailored for specific uses.
"Capturing atomic clusters inside patterned graphene nanopores could potentially lead to practical applications in areas such as electronic and optoelectronic devices, as well as catalysis," Lee said. "It would be a new approach to tuning electronic and optical properties in materials."
The ORNL team confirmed its experimental findings with theoretical calculations, which helped explain how much energy was required for the silicon atom to switch back and forth between different positions.
The study, published as "Direct visualization of reversible dynamics in a Si6 cluster embedded in a graphene pore," is available online here: http://www.nature.com/ncomms/journal/v4/n4/full/ncomms2671.html . Coauthors are ORNL's Jaekwang Lee, Wu Zhou, Stephen Pennycook, Juan Carlos Idrobo, and Sokrates Pantelides.
This research was supported by National Science Foundation, DOE's Office of Science, the McMinn Endowment at Vanderbilt University, and by DOE's Office of Science User Facilities: ORNL's Shared Research Equipment User Facility Program and the National Energy Research Scientific Computing Center at Lawrence Berkeley National Laboratory.
ORNL is managed by UT-Battelle for the Department of Energy's Office of Science. 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 http://science.energy.gov.
Morgan McCorkle | EurekAlert!
Move over, Superman! NIST method sees through concrete to detect early-stage corrosion
27.04.2017 | National Institute of Standards and Technology (NIST)
Control of molecular motion by metal-plated 3-D printed plastic pieces
27.04.2017 | Ecole Polytechnique Fédérale de Lausanne
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
27.04.2017 | Life Sciences
27.04.2017 | Physics and Astronomy
27.04.2017 | Earth Sciences