For the first time, scientists have a clearer understanding of how to control the appearance of a superconducting phase in a material, adding crucial fundamental knowledge and perhaps setting the stage for advances in the field of superconductivity. The paper focuses on a calcium-iron-arsenide single crystal, which has structural, thermodynamic and transport properties that can be varied through carefully controlled synthesis.
Scientists at Ames Laboratory have observed magnetic properties typically associated with those observed in rare-earth elements in iron. These properties are observed in a new iron based compound that does not contain rare earth elements, when the iron atom is positioned between two nitrogen atoms.
Using an ultra-fast laser system, a group in Physical and Life Sciences at Lawrence Livermore National Laboratory have subjected iron to extremely rapid dynamic compression and have shown that the transition from one crystal structure to another can take place in less than 100 trillionths of a second after the compression begins.
Ever-shrinking electronic devices could get down to atomic dimensions with the help of transition metal oxides. Researchers from Cornell Univ. and Brookhaven National Laboratory have shown how to switch a particular transition metal oxide, a lanthanum nickelate (LaNiO3), from a metal to an insulator by making the material less than a nanometer thick.
Scientists at Yale Univ. have devised a dramatically faster way of identifying and characterizing complex alloys known as bulk metallic glasses (BMGs), a versatile type of pliable glass that's stronger than steel. Using traditional methods, it usually takes a full day to identify a single metal alloy appropriate for making BMGs.
In the fight against “superbugs,” scientists have discovered a class of agents that can make some of the most notorious strains vulnerable to the same antibiotics that they once handily shrugged off. Recently discovered metallopolymers, when paired with the same antibiotics MRSA normally dispatches with ease, helped evade the bacteria’s defensive enzymes and destroyed its protective walls, causing the bacteria to burst.
Recent experiments in Austria have explained the behavior of electrons at tiny step edges on titanium oxide surfaces. The finding, which shows why oxygen atoms attach so well to these edges, is important for solar cell technology and novel, more effective catalysts.
In steel making, two desirable qualities, strength and ductility, tend to be at odds: Stronger steel is less ductile, and more ductile steel is not as strong. Engineers at Brown Univ., three Chinese universities, and the Chinese Academy of Sciences have shown that when cylinders of steel are twisted, their strength is improved without sacrificing ductility.
Researchers are turning some of the basic tenets of chemistry and physics upside down to cut a trail toward the discovery of a new set of materials. They’re called “polar metals” and, according to many scientific principles, they probably shouldn’t exist.
Biomass is a good alternative for fossil fuels, but converting biomass into useful chemicals and fuels is difficult in practice. The metal oxide CeO2 can help the process by activating water, but until recent research in the Netherlands, it was not clear in which form the reactivity of this catalyst was highest.
Researchers have discovered that creating a graphene-copper-graphene “sandwich” strongly enhances the heat conducting properties of copper, a discovery that could further help in the downscaling of electronics.
Using an inexpensive inkjet printer, Univ. of Utah electrical engineers produced microscopic structures that use light in metals to carry information. This new technique, which controls electrical conductivity within such microstructures, could be used to rapidly fabricate superfast components in electronic devices, make wireless technology faster or print magnetic materials.
Researchers from Empa and ETH Zurich have succeeded in producing a prototype of a vibration-damping material that could change the world of mechanics. The material of the future is not only able to damp vibrations completely; it can also specifically conduct certain frequencies further.
A big step in the development of advanced fuel cells and water-alkali electrolyzers has been achieved with the discovery of a new class of bimetallic nanocatalysts that are an order of magnitude higher in activity than the target set by the U.S. Department of Energy for 2017. The new catalysts feature a 3-D catalytic surface activity that makes them significantly more efficient and far less expensive than the best platinum catalysts.
It has long been known that free, ionic silver particles can be highly toxic to aquatic organisms. Yet we a lack of detailed knowledge about the doses required to trigger a response and how the organisms deal with the stress. To learn more about the cellular processes, scientists in Switzerland subjected algae to a range of silver concentrations. The results are reassuring, but the presence of other stressors could compound the problem.
Researchers at Argonne National Laboratory in collaboration with scientists at Northwestern Univ. are the first to grow graphene on silver which, until now, posed a major challenge to many in the field. Part of the issue has to do with the properties of silver, the other involves the process by which graphene is grown.
Mottronics is a term seemingly destined to become familiar to aficionados of electronic gadgets. Named for the Nobel laureate Nevill Francis Mott, Mottronics involve materials that can be induced to transition between electrically conductive and insulating phases. If these phase transitions can be controlled, Mott materials hold promise for future transistors and memories that feature higher energy efficiencies and faster switching speeds.
For four decades, polychlorinated biphenyls (PCBs) and heavy metals from nearby manufacturing plants flowed into New Bedford Harbor, creating one of the EPA’s largest Superfund cleanup sites. It’s also the site of an evolutionary puzzle: small Atlantic killifish are not only tolerating the toxic conditions in the harbor, they seem to be thriving there. In a new paper, researchers may have an explanation for their genetic resistance to PCBs.
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%.
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.
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.
Only a few elements in the periodic table are inherently magnetic, but scientists have recently discovered that gold, silver, platinum, palladium and other transition metals demonstrate magnetic behavior when formed into nanometer-scale structures. Scientists at the RIKEN Center for Emergent Matter Science have now shown that this nanoscale magnetism in thin films of platinum can be controlled using an externally applied electric field.
A team of researchers at the Univ. of Delaware has developed a highly selective catalyst capable of electrochemically converting carbon dioxide to carbon monoxide with 92% efficiency. The carbon monoxide then can be used to develop useful chemicals. The exceptionally high activity of the new electrocatalyst is due to its extremely large and highly curved internal surface.
By emitting photons from a quantum dot at the top of a micropyramid, researchers at Linköping Univ. in Sweden are creating a polarized light source for such things as energy-saving computer screens and wiretap-proof communications.
A new catalytic converter developed in the U.K. could cut fuel consumption and manufacturing costs significantly. Tests suggest that the new prototype, which uses up to 80% less rare metal than a conventional converter, could reduce fuel consumption in a standard vehicle by up to 3%. Metals such as platinum now account for 60 to 70% of the cost of the component.