Materials such as bismuth samarium ferrite and lead zirconium titanate are often called "materials on the brink" in reference to their enigmatic behavior, which is closely tied to the transition between two different phases. Recent electron microscopy sponsored by Oak Ridge National Laboratory has helped build knowledge about these materials and related flexoelectric theory, which describes materials that change polarization when bent.
Thermal stress can cause debonding between thin layers in microelectronics. Taking advantage of the force generated by magnetic repulsion, researchers have developed a new technique for measuring the adhesion strength between thin films of materials used in these devices, and they hope to apply the method improve solar cells or microelectromechanical devices.
Cornell materials scientists have developed an inexpensive, environmentally friendly way of synthesizing oxide crystal sheets, just nanometers thick, which have useful properties for electronics and alternative energy applications. Unlike typical oxides, these sheets are conducting, and could be ideal for use in thermoelectric devices to convert waste heat into power.
Powerful microprocessors in computers today use vast quantities of data and perform millions of calculations per second, but the connections simply cannot shift electrons fast enough. Wadimos, an effort in Europe to develop process technology for building wavelength division multiplexed photonic layers on CMOS chips is an effort to bring photon-fast performance to chip connections.
In prototypes of the lithium-sulfur battery, lithium ions are exchanged between lithium- and sulfur-carbon electrodes. The sulfur is an excellent energy storage material due to its low weight. At the same time, sulfur is a poor conductor, so researchers have a devised a way to greatly improve conductivity using a porous network of carbon nanoparticles.
A newly developed combination device for infrared spectroscopy has allowed researchers in Germany to conduct highly precise measurements of the vibration frequency of oxide materials at the surface. Surface defect analyses have previously been well-documented for metals, but materials such as titanium dioxide haven’t before been studied in such detail.
A team headed by Dr. Kazunari Yamaura at Japan’s National Institute for Materials Science has succeeded in the development of particularly strong and tough high temperature superconducting nanowires. Containing iron and arsenic, the wires, or “whiskers”, offer advantages over copper-oxide or fullerene-based whiskers which are either too brittle or have a limited aspect ratio.
Researchers in the U.K. have demonstrated that a honeycomb pattern of nano-sized magnets, in a material known as spin ice, introduces competition between neighboring magnets, and reduces the problems caused by these interactions by two-thirds. Large arrays of these nano-magnets, they say, can store computable information.
Using a simple liquid bath process, scientists at Natcore Technology Inc. have create have created a black surface on a silicon wafer with an average reflectance in the visible and near-infrared region of the solar spectrum of 0.3%, making it the "blackest" silicon solar cell surface ever recorded.
At this week’s American Chemical Society meeting in San Diego, Rice University chemist James Tour revealed a new device his laboratory has invented. Using silicon oxide as the active component, his team has made a transparent, flexible memory technology that could be combined with other see-through components such as integrated circuits and batteries.
Previous efforts to integrated lasers in silicon chips have relied on and air-and-semiconductor interface, but this has resulted in poor emission efficiency. Researchers in Singapore have invented a solution called a micro-loop mirror that acts as a waveguide to improve operation to 98% light reflection efficiency.
Scientists long have known that butterfly wings contain tiny scales that serve as natural solar collectors to enable butterflies, which cannot generate enough heat from their own metabolism, to remain active in the cold. Scientists in China have used this same structure, taken from a black butterfly to create a titanium dioxide-based device catalyst that significantly improved hydrogen production.
Addressing five decades of debate, Stanford University engineers have determine how collective electron oscillations, called plasmons, behave in individual metal particles as small as just a few nanometers in diameter. This knowledge may open up new avenues in nanotechnology ranging from solar catalysis to biomedical therapeutics.
So far, quantum bits have only existed in relatively large vacuum chambers. A research team in Germany, with help from colleagues in Japan and France, has now generated them in a high-quality gallium arsenide crystal.
Researchers at CRANN, a nanoscience institute based in Trinity College Dublin, have discovered a new material could fill a previously missing component in display electronics—a good quality p-type transparent conducting oxide.
Current approaches to organic electronics mainly involve plastic film supports with conducting paths and components made of organic molecules inexpensively printed or glued on. Researchers in Japan have made a new advance, using uncharged organic substances that are luminescent liquids at room temperature and require no solvent.
By depositing atoms on one side of a grid of the “miracle material” graphene, researchers at Stanford have engineered piezoelectricity into a nanoscale material for the first time. And the effect, which could dramatically affect electrical control of graphene materials, can be just as pronounced as in conventional 3D materials.
Just as a chameleon changes its color to blend in with its environment, Duke University engineers have demonstrated for the first time that they can alter the texture of plastics on demand, for example, switching back and forth between a rough surface and a smooth one.
Researchers at Helmholtz Center in Germany have developed a magnetic valve that could be an enabling technology for spintronics. The new structure allows for data to remain stored even after electric current has been cut, and memory in the valve can be re-written indefinitely.
Researchers at the Max Planck Institute have put together a sandwich of a ferroelectric layer between two ferromagnetic materials that responded to a short electric pulse. This changes the magnetic transport properties of the material in such a way that information can be placed in four states instead of just two. The potential increase in storage density is great.
For decades, scientists have known that some ferroelectric materials—materials that possess a stable electrical polarization switchable by an external electric field—are also photovoltaic. But scientists didn’t know how or why. Recent research has revealed an atomic-scale wiggle just 10 trillionths of a second long that reveals the mechanism for the materials’ photovoltaic effect.
Scientists using a variant of atomic force microscopy called Kelvin probe force microscopy, at low temperatures and in ultrahigh vacuum, have recently obtained the first image of the charge distribution within a single molecule. The molecule is the same as the type used in IBM’s single-molecule logic switch.
A long-standing controversy regarding the semiconductor gallium manganese arsenide, one of the most promising materials for spintronic technology, looks to have been resolved. Researchers with Lawrence Berkeley National Laboratory and Notre Dame University found the that the spintronic properties do not arise from a valence energy band, as many scientists have argued.
Made from carbon nanotubes locked up in flexible plastic fibers and made to feel like fabric, an invention called Power Felt from Wake Forest University uses temperature differences—room temperature versus body temperature, for example—to create a charge.
Complex transition metal oxides have for years held great promise for information and energy applications, but reducing the band gaps of these insulators without hurting performance has been a major challenge. A recent layer-by-layer growth method pioneered at Oak Ridge National Laboratory has achieved a 30% reduction in this band gap, a significant improvement.