Image: D. Hornbaker and A. Yazdani
In yet another small step toward building nanoscale devices, scientists have determined that nanotube peapods — minute straws of carbon filled with spherical carbon molecules known as buckyballs — have tunable electronic properties. Published online by the journal Science,the findings suggest that stuffing the straws provides greater control over the electronic states of single-walled carbon nanotubes (SWNT).
Using a low-temperature scanning tunneling microscope, Ali Yazdani of the University of Illinois at Urbana-Champaign and colleagues imaged the physical structure of individual peapods (right). They mapped the motion of electrons within the pipes and, as Yazdani explains, showed "that an ordered array of encapsulated molecules can be used to engineer electron motion inside nanotubes in a predictable way." Though the harbored buckyballs modify the electronic properties of the nanotube, the atomic structure of the straw remains unchanged.
The researchers also utilized the microscope to move the buckyballs, which allowed them to compare the same section of a SWNT when it was filled and unfilled. "The encapsulated balls have a much stronger effect on the electronic structure of the tube than we had expected," says study co-author Eugene Mele of the University of Pennsylvania. Indeed, the authors conclude that their calculation not only shows how a peapod’s electronic properties differ from those of its constituent parts, "it also provides possible design rules for proposing hybrid structures having a specific type of electronic functionality."
Sarah Graham | Scientific American
For graphite pellets, just add elbow grease
23.03.2018 | Rice University
23.03.2018 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA
Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
23.03.2018 | Event News
19.03.2018 | Event News
16.03.2018 | Event News
23.03.2018 | Materials Sciences
23.03.2018 | Agricultural and Forestry Science
23.03.2018 | Physics and Astronomy