Superconductor “recipes” are frequently tweaked by swapping out elements or manipulating the valence electrons to strike the perfect conductive balance. Most high-temperature superconductors feature only one orbital impacting performance. But what about introducing more complex configurations? Now, Brookhaven National Laboratory’s physicists have combined atoms with multiple orbitals and precisely pinned down their electron distributions.
An undesired effect in thin film amorphous silicon solar cells has puzzled the scientific community for the last 40 years. This effect, known as light-induced degradation, is responsible for reducing solar cell efficiency over time. Researchers in Germany have recently demonstrated that tiny voids within the silicon network are partly responsible for 10 to 15% efficiency loss as soon as they are used.
A team in France has greatly miniaturized the light-emitting diode (LED) by creating one from a single polythiophene wire placed between the tip of a scanning tunneling microscope and a gold surface. This nanowire, which is made of the same hydrogen, carbon and sulfur components found in much larger LEDs, emits light only when the current passes in a certain direction.
Modern electronics relies on utilizing the charge properties of the electron. The emerging field of atomtronics, however, uses ensembles of atoms to build analogs to electronic circuit elements. Physicists have built a superfluid atomtronic circuit that have allowed them to demonstrate a tool that is critical to electronics: hysteresis. It is the first time that hysteresis has been observed in an ultracold atomic gas.
New research at the Univ. of Arkansas reveals a novel magnetoelectric effect that makes it possible to control magnetism with an electric field. The novel mechanism may provide a new route for using multiferroic materials for the application of RAM (random access memories) in computers and other devices, such as printers.
An international partnerships is aiming to develop robust fingerprint sensors with resolution beyond today’s 500 dpi international standards, the minimum required by the U.S. Federal Bureau of Investigation. The new platform uses vertical piezoelectric nanowire matrices designed using multiphysics modeling software.
An international team has recently unveiled a superconducting pairing mechanism in calcium-doped graphene. The pairing, which was using a angle-resolved photoemission spectroscopy method, is important because graphene is easily doped or functionalized with chemicals, allowing scientists to more fully explore the nature of superconductivity.
Engineers are increasingly turning to plasmonic color filters (PCFs) to create and control a broad spectrum of colors for imaging applications. However, PCF light transmission efficiency has been limited to only about 30%, less than half the rate of conventional filters. Researchers have now developed a new PCF scheme that achieves a transmission efficiency of 60 to 70%.
NIST and American Univ. researchers report in a new study that the bench-scale test widely used to evaluate whether a burning cigarette will ignite upholstered furniture may underestimate the tendency of component materials to smolder when these materials are used in sofas and chairs supported by springs or cloth. The study comes as regulations and methods for evaluating ignition in furniture are undergoing scrutiny.
Materials experts in Ireland have developed a new germanium nanowire-based anode that has the ability to greatly increase the capacity and lifetimes of lithium-ion batteries. The typical lithium-ion battery on the market today is based on graphite, which has a relatively low capacity for energy storage. Restructuring the germanium replacement material into nanowires produces a stable, porous battery material.
U.S. Army-sponsored researchers have discovered a process for simultaneously storing and dissipating energy within structures that could lead to design rules for new types of active, reconfigurable materials. The study method was derived from an examination of how a species of South American fire ant collectively entangle themselves to form an active structure capable of changing state from a liquid to a solid when subject to applied loads.
Topological insulators have been of great interest to physicists in recent years because of unusual properties that may provide insights into quantum physics. But most analysis of such materials has had to rely on highly simplified models. Now, a team of researchers at Massachusetts Institute of Technology has performed a more detailed analysis that hints at the existence of six new kinds of topological insulators.
Lead-free BaTiO3 and KNbO3 ferroelectrics have been known and studied for more than 60 years. However, recent scanning x-ray diffraction studies at Argonne National Laboratory have shown new low-symmetry intermediate phases in these materials that lend a thermotropic character to otherwise well-known phase transitions. The findings show that these transitions in ferroelectrics are closely coupled to the underlying domain microstructure.
An international team of researchers from France and the United States have devised an entirely new way to synthesize graphene ribbons with defined, regular edges, allowing electrons to flow freely through the material. Demonstrating this phenomenon at room temperature, the material was shown to permit electron flow up to 200 times faster than through silicon.
Texas Advanced Computing Center recently reported the results of several massive numerical simulations charting the forces of the universe in its first hundreds of millions of years. The study, which used some of the world's most powerful supercomputers, has refined our understanding of how the first galaxies formed, and, in particular, how metals in the stellar nurseries influenced the characteristics of the stars in the first galaxies.
Working on the cutting edge of a newly emerging area of solar-cell research, Univ. of California, Los Angeles engineers have invented a new process for manufacturing highly efficient photovoltaic materials that shows promise for low-cost industrial production. The new process uses so-called perovskite materials, which in the past few years have significantly advanced scientists' efforts to create the next generation of solar cells.
We all learn in high school science about the dual nature of light—that it exists as both waves and quantum particles called photons. It’s this duality of light that enables the coherent transport of photons in lasers. Sound at the atomic-scale has the same dual nature, existing as both waves and quasi-particles known as phonons. Does this duality allow for phonon-based lasers?
Researchers at Tyndall National Institute in Ireland have produced the first ever atom-by-atom simulation of nanoscale film growth by atomic layer deposition (ALD), a thin-film technology used in the production of silicon chips. The accomplishment required the acquisition of the complete set of hundreds of ALD reactions at the quantum mechanical level.
Individual silver nanoparticles in solutions typically grow through single atom attachment, but when they reach a certain size they can link with other particles, according to a team which includes scientists at Pacific Northwest National Laboratory. This seemingly simple result has shifted a long-held scientific paradigm that did not consider kinetic models when explaining how nanoparticle ensembles formed.
Look out, super glue and paint thinner. Thanks to new dynamic materials developed at the Univ. of Illinois, removable paint and self-healing plastics soon could be household products. Other self-healing material systems have focused on solid, strong materials, but this new study uses softer elastic materials made of polyurea, one of the most widely used classes of polymers in consumer goods such as paints, coatings, elastics and plastics.
New research shows that a remarkable defect in synthetic diamond produced by chemical vapor deposition allows researchers to measure, witness, and potentially manipulate electrons in a manner that could lead to new “quantum technology” for information processing.
Trying to find new materials, to improve the performance of anything from microchips to car bodies, has always been a process of trial and error. Massachusetts Institute of Technology materials scientist Gerbrand Ceder likens it to setting out from Boston for California, with neither a map nor a navigation system—and on foot.
In a world’s first, researchers at the National Institute of Materials Science in Japan have succeeded in controlling the length of a one-dimensional, or supramolecular, assembly of molecules. Their method involves molecular self-organization, which until now has not been practical for polymer synthesis because of a lack of knowledge about the interplay of organizational pathways.
Scientists have used a particle physics theory to describe the behavior of particle-like entities, referred to as excitons, in two layers of graphene. The use of equations typically employed in high-energy physics has prompted the authors to suggest a design for an experimental device relying on a magnetically tunable optical filter that could verify their predictions.
Perfect sheets of diamond a few atoms thick appear to be possible even without the big squeeze that makes natural gems. Scientists have speculated about it and a few laboratories have even seen signs of what they call diamane, an extremely thin film of diamond that has all of diamond’s superior semiconducting and thermal properties.