After studies involving advanced simulations of nanoscale magnetic and materials phenomena, a team of scientists in Germany have proposed making use of magnetic moments in chains of iron atoms to allow information to be transported on the nanoscale in a fast and energy-efficient manner. The scheme, demonstrated in experiments, would work over a wide temperature range, remaining largely unaffected by external magnetic fields.
A detailed description of development of the first practical device that mimics the process of photosynthesis has recently been published in an American Chemical Society journal. Unlike earlier devices, which used costly ingredients, the new device is made from inexpensive materials and employs low-cost engineering and manufacturing processes.
Gallium nitride, a semiconductor material found in bright lights since the 1990s, is used in wireless applications because of its high efficiency and high voltage operation. However, it’s difficult to remove heat from GaN electronics, which limits applications and markets. Researchers at the University of California, Riverside, have made a material from graphene that does the job, and it looks a lot like a patterned quilt.
White-light quantum dots made from cadmium selenide can convert blue light produced by a light-emitting diode into a warm white light similar to that generated by an incandescent bulb. But their performance has been poor until recent development breakthroughs have improved efficiency from just 3% originally to as high as 45%.
The performance of magnetic storage devices is limited by the way magnetic domains interact when in close proximity. 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.
By using diamond-tipped tools to apply pressure, a team led by Johns Hopkins engineers has discovered some previously unknown electrical properties of a common memory material, a mix of germanium, antimony, and tellurium called GST. The discovery should make GST more useful for electronics developers by allowing memory formats that retain data more quickly, last longer, and allow far more capacity.
Scientists from Imperial College London have collaborated with colleagues at King Abdullah University of Science and Technology in Saudi Arabia to produce organic thin-film transistors that consistently achieve record-breaking carrier mobility through careful solution-processing of a blend of two organic semiconductors.
An international team of researchers studying a superconducting strip have observed an intermittent motion of magnetic flux which carries vortices inside the regularly spaced weak conducting regions carved into the superconducting material. These tiny interactions help govern the electronic behavior of superconductors, offering potential applications for voltage measurement techniques.
Engineers at Stanford University have found a novel method for “decorating” nanowires with chains of tiny particles to increase their electrical and catalytic performance. The new technique is simpler, faster and provides greater control than earlier methods and could lead to better batteries, solar cells and catalysts.
In collaboration with researchers in Japan, U.K. scientists have grown highly boron-doped diamond layers just 1 nm in thickness. The technique is known as d-doping, and the researchers believe the layers will be the basis for high-performance field-effect transistors that offer the prospect of highly sensitive biochemical agent detection.
Until the development of a new nanomaterial-based sensor in Germany, the brain’s magnetic field was measurable only under technical laboratory conditions. This prevented the technology’s use in medical applications. The new sensors, however, operate at normal conditions. Neither cooling nor external magnetic bias fields are required.
Silicon germanium (SiGe) has been valued for its performance in high-temperature thermoelectric applications, but its low-temperature performance and high cost have prevented broader applications. By altering the design of bulk SiGe with a process borrowed from the thin-film semiconductor industry, however, researchers have substantially increased its electrical conductivity.
A new study finds that "quantum critical points" in exotic electronic materials can act much like polarizing "hot button issues" in an election. Researchers found that on either side of a quantum critical point, electrons fall into line and behave as traditionally expected, but at the critical point itself, traditional physical laws break down.
Using a self-assembly method that combines synthetic molecules typically used in photocopying, researchers in France and Germany have made highly conductive plastic fibers that are only several nanometers thick.
Theoretically, a solar cell can achieve 33.5% efficiency under ideal conditions, but until now researchers had hit only 26%. This past year, a company called Alta Devices acted on the theory that emission and voltage go hand-in-hand by creating solar cell that acts like a light-emitting diode. Its prototype broke the record, achieving 28.3% efficiency.
A team of researchers from Taiwan and the University of California, Berkeley, has harnessed nanodots, just 3 nm in diameter, to create a new electronic memory technology that can write and erase data 10 to 100 times faster than today's mainstream charge-storage memory products.
A collaboration between Tsinghua University in China and Rice University has produced a potentially low-cost, efficient alternative to silicon-based solar cells. Single-wall nanotube arrays, grown in a process invented at Rice, have been shown in recent studies to be more electroactive and potentially cheaper than platinum, a common catalyst in dye-sensitized solar cells.
Engineers at Purdue University have coated glass fibers with a new thermoelectric material formed by dipping glass fibers in a solution containing nanocrystals of lead telluride and then exposing them to heat in a process called annealing to fuse the crystals together. The resulting material is far less brittle and more effiicient to produce than conventional thermoelectrics.
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.