Flawed but colorful diamonds are among the most sensitive detectors of magnetic fields known today, allowing physicists to explore the minuscule magnetic fields in metals, exotic materials and even human tissue. A team of physicists have now shown that these diamond sensors can measure the tiny magnetic fields in high-temperature superconductors, providing a new tool to probe these much ballyhooed but poorly understood 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.
The huge surface area and strong interactions between graphene layers causes facile “stacking” behavior that dramatically reduces available surface area, inhibiting graphene electronic properties. Researchers have tried to prevent this with carbon black, but this also carries undesirable property changes. By introducing protuberances on graphene during synthesis, researchers in China have found a solution to the stacking problem.
In physics, there's small, and then there's nullity, as in zero-dimensional. Univ. of Cincinnati researchers have reached this threshold with a special structure, zero-dimensional quantum dots, that may someday lead to better ways of harnessing solar energy, stronger lasers or more sensitive medical diagnostic devices.
Scientists at Los Alamos National Laboratory are working toward even stronger and more elastic glass types which would fail in a ductile fashion instead of shattering. Researchers there are looking at the initiation of shear-banding events in order to better understand how to control the mechanical properties of these materials.
A key to realizing commercial-scale artificial photosynthesis technology is the development of electrocatalysts that can efficiently and economically carry out water oxidation reaction that is critical to the process. Heinz Frei, a chemist Lawrence Berkeley National Laboratory, has been at the forefront of this research effort. His latest results represent an important step forward.
Current technologies for writing, storing, and reading information are either charge-based or spin-based. The downside is that weak perturbations such as impurities or radiation can lead to uncontrolled charge redistributions and, as a consequence, to data loss. Researchers in Europe have predicted and discovered a new physical phenomenon that allows them to manipulate the state of a magnet by electric signals and eliminate this loss.
According to recent findings by an international team of computer engineers, optical data storage does not require expensive magnetic materials because synthetic alternatives work just as well. The team’s discovery that synthetic ferrimagnets can be switched optically brings a much cheaper method for storing data using light a step closer.
Scientists at Ames Laboratory are revealing the mysteries of new materials using ultra-fast laser spectroscopy. Researchers recently used ultra-fast laser spectroscopy to examine and explain the mysterious electronic properties of iron-based superconductors. Seeing these dynamics is one emerging strategy to better understanding how these new materials work.
U.K. scientists have succeeded in measuring how the surfaces of glassy materials flow like a liquid, even when they should be solid. A series of simple and elegant experiments were the solution to a problem that has been plaguing condensed matter physicists for the past 20 years. The finding has implications for thin-film coating designs.
A team of researchers has developed a material that could help prevent blood clots associated with catheters, heart valves, vascular grafts and other implanted biomedical devices. Blood clots at or near implanted devices are thought to occur when the flow of nitric oxide, a naturally occurring clot-preventing agent generated in the blood vessels, is cut off. When this occurs, the devices can fail.
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.
Ultraviolet light (UV) has not only harmful effects on molecules and biological tissue like human skin but it also can impair the performance of organic solar cells upon long-term exposure. Researchers in Germany have now developed a so-called plasmonic metamaterial which is compatible with solar technology and completely absorbs UV light despite being only 20 nm thin.
How heat flows at the nanoscale can be very different than at larger scales, and researchers are working to understand how these features affect the transport of the fundamental units of heat, called phonons. At Cornell Univ. scientists have invented a phonon spectrometer whose measurements are 10 times sharper than standard methods. This boosted sensitivity has uncovered never-before-seen effects of phonon transport.
Cornell Univ. researchers have recently led what is probably the most comprehensive study to date of block copolymer nanoparticle self-assembly processes. The work is important, because using polymers to self-assemble inorganic nanoparticles into porous structures could revolutionize electronics.
A Chinese-U.S. research team is exploring the use of metamaterials to create devices that manipulate sound in versatile and unprecedented ways. In a recently published paper, the team reports a simple design for a device, called an acoustic field rotator, which can twist wave fronts inside it so that they appear to be propagating from another direction.
While taking in the scenery during long road trips, passengers also may be taking in potentially harmful ultrafine particles (UFPs) that come into the car through outdoor air vents. Closing the vents reduces UFPs, but causes exhaled carbon dioxide to build up. Now, scientists have developed a high-efficiency cabin air filter that could reduce UFP exposure by 93% and keep carbon dioxide levels low.
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.
When deciding what materials to use in building something, determining how those materials respond to stress and strain is often the first task. A material’s macroscopic, or bulk, properties in this area is generally the product of what is happening on a microscopic scale. When stress causes a material’s constituent molecules to rearrange in a way such that they can't go back to their original positions, it is known as plastic deformation.
To attach itself to surfaces, the marine sponge Monorhaphis chuni forms an unusual glass rod. Researchers have recently analyzed the nanostructure of the filament passing through the center of this glass rod and discovered that it is formed with a perfect periodic arrangement of nanopores. In this way, the sponge employs a similar method that is now used for fabrication of man-made mesoporous nanomaterials.
Previous efforts to create graphene nanoribbons followed a top-down approach, using lithography and etching process to try to cut ribbons out of graphene sheets. Cutting ribbons 2 nm-wide is not practical, however, and these efforts have not been very successful. Now, a research team has developed a chemical approach to mass producing these graphene nanoribbons. This process that may provide an avenue to harnessing graphene's conductivity.
Researchers in the U.K. have developed a method of controlling the composition of a range of polymers, the large molecules that are commonly used as plastics and fibers. They have demonstrated how the chemical reactions can be manipulated, especially in fixing the composition of a polymer using a mixture of up to three different monomers. The secret lies in understanding and switching “on” and “off” the catalyst used to make the polymers.
The scarcity of ultraviolet (UV) light in sunlight has held back the usefulness of titanium dioxide-based photocatalysts. Through the application of nanotechnology, researchers in Japan have recently succeeded in the development of better titanium dioxide-based material that can be activated by visible light. The solution lies in an array of nanoparticles that “simulate” the photoexcitation of UV light.
Computers don’t need to be error-free. They just need to correct their errors reliably, which means that controlling a quantum system is crucial to the function of a quantum computer. A research team has now found a way to control the quantum system of a diamond which has a few nitrogen impurities. They have used the system to perform a logic operation and error correction in a quantum register made from nuclear spins of the gemstone.