While freestanding graphene offers promise as a replacement for silicon and other materials in microprocessors and next-generation energy devices, much remains unknown about its mechanical and thermal properties. An international team of physicists, led by a research group at the Univ. of Arkansas, has recently discovered that heating can be used to control the curvature of ripples in freestanding graphene.
A comprehensive look at how tiny particles in a lithium-ion battery electrode behave shows that...
Plastics are made of polymers, which are a challenge for scientists to study. Their chain-like strands of thousands of atoms are tangled up in a spaghetti-like jumble, their motion can be measured at many time scales and they are essentially invisible to some common x-ray study techniques. A better understanding of polymers at the molecular scale could lead to improved manufacturing techniques and the creation of new materials.
On the macroscale, adding fluorine atoms to carbon-based materials makes for water-repellant, non-stick surfaces, such as Teflon. However, on the nanoscale, adding fluorine to graphene vastly increased the friction experienced when sliding against the material. Through a combination of physical experiments and atomistic simulations, a Univ. of Pennsylvania research team has discovered the mechanism behind this surprising finding.
A new concept in metallic alloy design has yielded a multiple-element material that not only tests out as one of the toughest on record, but, unlike most materials, the toughness as well as the strength and ductility of this alloy actually improves at cryogenic temperatures. This multi-element alloy was synthesized and tested through a collaboration of researchers.
Researchers at Oak Ridge National Laboratory got a surprise when they built a highly ordered lattice by layering thin films containing lanthanum, strontium, oxygen and iron. Although each layer had an intrinsically nonpolar distribution of electrical charges, the lattice had an asymmetric distribution of charges.
The most familiar photovoltaic (PV) designs use rigid layers of silicon crystal, but recently inexpensive organic semiconductor materials have also been used successfully. At this time, organic PV devices are hindered by low efficiency, in part because quantifying their electrical properties is a challenge. Researchers have now developed a method that allows the prediction of the current density-voltage curve of a photovoltaic device.
A team of researchers in the U.S. and China have developed a new sensor that can detect and count nanoparticles, at sizes as small as 10 nm, one at a time. The researchers say the sensor, which is a Raman microlaser sensor in a silicon dioxide chip that does not need rare-earth ions to achieve high resolution, could potentially detect much smaller particles, viruses and small molecules.
Researchers have discussed the merits of surface-stress influence on mechanical properties for decades. Now, a new research platform, called nanomechanical Raman spectroscopy and developed at Purdue Univ., uses a laser to measure the "nanomechanical" properties of tiny structures undergoing stress and heating.
Bridges become an infrastructure problem as they get older, as de-icing salt and carbon dioxide gradually destroy the reinforced concrete. A new robot called C2D2 (Climbing Corrosion Detecting Device) is now in use in Switzerland and can check the condition of these structures, even in places that people cannot reach.
A team of scientists from Germany, Canada, and the United States has now developed a promising new measurement method that works without destroying anything yet offers nanoscale resolution. The method, an enhancement of resonant x-ray reflectometry identifies the chemical elements involved and is able to determine both the magnetic order and the electron distribution.
A mechanical engineering student at EPFL in Switzerland wanted to understand the reason behind the formation of a “foam volcano” after tapping the neck of a bottle of beer. He studied the phenomenon with a high-speed camera and compared it to the outcome of applying the same action to sparkling water. His work offers insights into the behavior of cavitation nuclei.
Electronic devices with unprecedented efficiency and data storage may someday run on ferroelectrics—remarkable materials that use built-in electric polarizations to read and write digital information, outperforming the magnets inside most popular data-driven technology. But ferroelectrics must first overcome a few key stumbling blocks, including a curious habit of "forgetting" stored data.
Since 2006, when NASA’s Stardust spacecraft delivered its aerogel and aluminum foil dust collectors back to Earth, a team of scientists has combed through them. They now report finding seven dust motes that probably came from outside our solar system, perhaps created in a supernova explosion and altered by eons of exposure to the extremes of space. They would be the first confirmed samples of contemporary interstellar dust.
The physical properties of the ultra-white scales on certain species of beetle could be used to make whiter paper, plastics and paints, while using far less material than is used in current manufacturing methods. Current technology is not able to produce a coating as white as these beetles can in such a thin layer, and spectroscopic analyses are revealing how this colorization is achieved through a dense complex network of chitin.
The “Bearded Man, 170-180 A.D.” is a Roman-Egyptian portrait that adorned the sarcophagus sheltering his mummified remains. The details of who he was have been lost to time, but a microscopic sliver of painted wood could hold the keys to unraveling the first part of this centuries-old mystery. Figuring out what kind of pigment was used, and the exact materials used to create it, could help scientists unlock his identity.
Graphene may be tough, but those who handle it had better be tender. The environment surrounding the atom-thick carbon material can influence its electronic performance, according to researchers at Rice and Osaka universities who have come up with a simple way to spot contaminants.
Zeolites used extensively in industry are promising catalysts that turn biomass into transportation fuels, but the activity and stability of this class of materials is challenging to understand and predict. Employing a combination of methods devised at Pacific Northwest National Laboratory and the Swiss Light Source, scientists were able to determine the distribution of aluminum ions in structural variants of zeolites.
Researchers at the National Physical Laboratory in the U.K. have discovered that the conductivity at the edges of graphene devices is different to the central material. The group used local scanning electrical techniques to examine the local nanoscale electronic properties of epitaxial graphene, in particular the differences between the edges and central parts of graphene Hall bar devices.
Traditional lithography is based on a simple principle: Oil and water don’t mix. The method, first developed by an actor in Bavaria in 1796, used a smooth piece of limestone on which an oil-based image was drawn and overlayed with gum arabic in water. During printing, the ink was attracted to the oil, and was repelled by the gum.
The engineering of functional systems at the molecular scale, nanotechnology refers to the applied part of nanoscience which typically includes the engineering to control, manipulate and structure matter at an atomically small scale. Nanotechnology as a field is nothing less than diverse, ranging from extensions of conventional device physics to new approaches based upon molecular self-assembly.
The search for zero-resistance conductors that can operate at realistic temperatures has been frustrated by the inability to understand high-temperature superconductors, particularly their magnetic structure. Researchers have done this at the atomic scale for the first time with a so-called strongly correlated electron system of iron telluride. Previously, magnetic information was provided by neutron diffraction, which is imprecise.
Using a new method to track the electrochemical reactions in a common electric vehicle battery material under operating conditions, scientists at Brookhaven National Laboratory have revealed new insight into why fast charging inhibits this material's performance. The study also provides the first direct experimental evidence to support a particular model of the electrochemical reaction.
Reactions among minerals and organic compounds in hydrothermal environments are critical components of the Earth’s deep carbon cycle. They provide energy for the deep biosphere, and may have implications for the origins of life. However, very little is known about how minerals influence organic reactions. A team of researchers has demonstrated how a common mineral acts as a catalyst for specific hydrothermal organic reactions.
A wildly bouncing tennis ball that travels a millions times the distance of its own size would be difficult to measure. But attaching the same ball to a measuring device would eliminate the “noise”. Researchers in Israel recently used a similar trick to measure the interaction between the smallest possible magnets (two electrons) after neutralizing magnetic noise that was a million times stronger than the signal they needed to detect.
A novel combination of microscopy and data processing has given researchers at Oak Ridge National Laboratory (ORNL) an unprecedented look at the surface of a material known for its unusual physical and electrochemical properties. The research team led by ORNL’s Zheng Gai examined how oxygen affects the surface of a perovskite manganite, a complex material that exhibits dramatic magnetic and electronic behavior.
A new method that uses x-rays for the rapid identification of substances present in an indeterminate powder has been developed by a scientist in Denmark. The new technique has the capacity to recognize advanced biological molecules such as proteins, which makes it potentially important in both food production and the pharmaceutical industry, where it opens up new opportunities for the quality assurance of protein-based medicines.
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