Using a new trick, researchers in Germany have been able to induce synchronous motion of the domain walls in a ferromagnetic nanowire. This is an important breakthrough for controlled movement of domain walls that allows permanent data to be stored using nanomagnets. The advance involved applying a pulsed magnetic field that was perpendicular to the plane of the domain walls.
New research shows that nanostructures could enable more light to be directed into the active layer of solar cells, increasing their efficiency. Prof. Martina Schmid of Freie Univ. in Berlin has measured how irregularly distributed silver particles influence the absorption of light. Nanoparticles interact with one another via their electromagnetic near-fields, so that local “hot spots” arise where light is concentrated especially strongly.
Nanoengineering researchers at Rice Univ. and Nanyang Technological Univ. in Singapore have unveiled a potentially scalable method for making one-atom-thick layers of molybdenum diselenide—a highly sought semiconductor that is similar to graphene but has better properties for making certain electronic devices like switchable transistors and light-emitting diodes.
Materials scientists have long known that introducing defects into 3-D materials can improve their mechanical and electronic properties. Now a new Northwestern Univ. study finds how defects affect 2-D crystalline structures, and the results hold information for designing new materials.
A new theoretical study shows the conductivity conditions under which graphene nanoribbons can become switches in externally controlled electronic devices. The results, obtained by researchers in Argentina and Brazil, yield a clearer theoretical understanding of conductivity in graphene samples of finite size, which have applications in externally controlled electronic devices.
Solid-state dye-sensitized solar cells have shown their potential in achieving high efficiency with a low cost of fabrication. Degradation of these cells shortens lifespan dramatically, however, and the causes of this are not well understood. After a detailed analysis, researchers in Okinawa have determined which material in the cells was degrading, and why.
Chemists have found that cellulose, the most abundant organic polymer on Earth, can be heated in a furnace in the presence of ammonia and turned into the building blocks for supercapacitors. The new process produces nitrogen-doped, nanoporous carbon membranes, which act as the electrodes of a supercapacitor. The only byproduct is methane, which could be used immediately as a fuel or for other purposes.
Carbon nanotubes are reinforcing bars that make 2-D graphene much easier to handle in a new hybrid material grown by researchers at Rice Univ. The Rice laboratory of chemist James Tour set nanotubes into graphene in a way that not only mimics how steel rebar is used in concrete but also preserves and even improves the electrical and mechanical qualities of both.
A combined computational and experimental study of self-assembled silver-based structures known as superlattices has revealed an unusual and unexpected behavior: arrays of gear-like molecular-scale machines that rotate in unison when pressure is applied to them.
A medical device, once its job is done, could harmlessly melt away inside a person’s body. Or, a military device could collect and send its data and then dissolve away, leaving no trace of an intelligence mission. Or, an environmental sensor could collect climate information, then wash away in the rain. It’s a new way of looking at electronics.
A new approach to studying solar panel absorber materials has been developed by researchers in France. The technique could accelerate the development of non-toxic and readily available alternatives to current absorbers in thin film-based solar cells.
Recent research in Japan, China and U.S. has revealed through theoretical simulations that the molecular mechanism of carbon nanotube growth and hydrocarbon combustion actually share many similarities. In studies using acetylene molecules as feedstock, a highly reactive molecular intermediate was found to play an important role in both processes forming CNTs and soot, which are two distinctively different structures.
Germanium monosulfide (GeS) is emerging as one of the most important class "IV–VI" semiconductor materials with potential in optoelectronics applications for telecommunications and computing. Adding a new element of control to preparation of this material, researchers in China have found a convenient way to selectively prepare GeS nanostructures, including nanosheets and nanowires, that are more active than their bulk counterparts
Combatting the tissue degrading enzymes that cause lasting damage following a heart attack is tricky. Each patient responds to a heart attack differently and damage can vary from one part of the heart muscle to another, but existing treatments can’t be fine-tuned to deal with this variation. Univ. of Pennsylvania researchers have developed a way to address this problem via a material that can be applied directly to the damaged heart tissue.
The fundamental laws of thermodynamics do not apply to objects on the nanoscale to the extent they do in our macroscopic world, and researchers are working to accurately describe the differences. A team of scientists have recently made progress in this area by determining how heat transfers from cold to hot objects in the nanoworld.
Interest in oxide-based semiconductor electronics has exploded in recent years, fueled largely by the ability to grow atomically precise layers of various oxide materials. One of the most important materials in this burgeoning field is strontium titanate, a nominally nonmagnetic wide-bandgap semiconductor, and researchers have found a way to magnetize this material using light, an effect that persists for hours at a time.
Polymer materials are usually thermal insulators. But by harnessing an electropolymerization process to produce aligned arrays of polymer nanofibers, researchers have developed a thermal interface material able to conduct heat 20 times better than the original polymer. The modified material can reliably operate at temperatures of up to 200 C.
Until now, it has been hard to couple light generation into layered semiconductor systems. Scientists in Austria have recently solved this problem using metamaterials, which are able to manipulate light in the terahertz range due to their special microscopic structure. This represents the first combination of metamaterials and quantum cascade structures.
Because of their unique qualities, thermoelectric materials can convert waste heat into electricity. Researchers in the Netherlands have managed to significantly improve the efficiency of a common thermoelectric material by adjusting the fabrication conditions. The material may eventually be used to, for example, put the heat issued from a factory chimney or car exhaust pipe to good use.
Scientists at Brookhaven National Laboratory have made the first 3-D observations of how the structure of a lithium-ion battery anode evolves at the nanoscale in a real battery cell as it discharges and recharges. The details of this research, described in a paper published in Angewandte Chemie, could point to new ways to engineer battery materials to increase the capacity and lifetime of rechargeable batteries.
Nanotechnology is advancing tools likened to Star Trek's "tricorder" that perform on-the-spot chemical analysis for a range of applications including medical testing, explosives detection and food safety. Researchers found that when paper used to collect a sample was coated with carbon nanotubes, the voltage required was 1,000 times reduced, the signal was sharpened and the equipment was able to capture far more delicate molecules.
In what was almost a chance discovery, researchers in Singapore have developed a solar cell material which can emit light in addition to converting light to electricity. This solar cell is developed from perovskite, a promising material that could hold the key to creating high-efficiency, inexpensive solar cells. The new cells not only glow when electricity passes through them, they can also be customized to emit different colours.
Whether traditional or derived from high technology, ceramics all have the same flaw: they are fragile. But now researchers in France have recently presented a new ceramic material inspired by mother-of-pearl from the small single-shelled marine mollusk abalone. This material, almost ten times stronger than a conventional ceramic, is the result of an innovative manufacturing process that includes a freezing step.
Researchers at NIST have devised an idea for determining the 3-D shape of features as small as 10-nm wide. The model-based method compares data from scanning electron microscope images with stored entries in a library of 3-D shapes to find a match and to determine the shape of the sample. The work provides a powerful new way to characterize nanostructures.
Researchers in the U.K. have developed a new antibacterial material which has potential for cutting hospital acquired infections. The combination of two simple dyes with nanoscopic particles of gold is deadly to bacteria when activated by light, even under modest indoor lighting. And in a first for this type of substance, it also shows impressive antibacterial properties in total darkness.