Understanding superconductivity has proved to be one of the most persistent problems in modern physics. Scientists have struggled for decades to develop a cohesive theory of superconductivity, largely spurred by the game-changing prospect of creating a superconductor that works at room temperature, but it has proved to be a tremendous tangle of complex physics.
Ferroelectric materials are known for their ability to spontaneously switch polarization when an electric field is applied. An Oak Ridge National Laboratory-led team took advantage of this property to draw areas of switched polarization called domains on the surface of a ferroelectric material. To the researchers’ surprise, the domains began forming complex and unpredictable patterns that the researchers say should not be possible.
Batteries that power electric cars have problems. They take a long time to charge. The charge doesn’t hold long enough to drive long distances. They don’t allow drivers to quickly accelerate. They are big and bulky. By creating nanoparticles with controlled shape, engineers in California believe smaller, more powerful and energy-efficient batteries for vehicles can be built.
Northwestern Univ. and Argonne National Laboratory scientists have recently overcome problems with growing graphene on chemically inert substrates, demonstrating the first growth of graphene on a single-crystal silver substrate. Their method could advance graphene-based optical devices and enable the interfacing of graphene with other two-dimensional materials.
One of the methods used for examining the molecules in a liquid consists in passing the fluid through a nano-sized hole so as to detect their passage. Researchers in Switzerland have found a way to improve this technique by using a material with unique properties: graphene.
An interdisciplinary team of researchers has set its sights on improving the materials that make solar energy conversion/photocatalysis possible. Together, they have developed a new form of high-performance solar photocatalyst based on the combination of the titanium dioxide and other “metallic” oxides that greatly enhance the visible light absorption and promote more efficient utilization of the solar spectrum for energy applications.
A team of scientists have demonstrated new application of graphene using positive feedback. Using graphene’s electrical conduction, Columbia Univ. engineers have created a nano-mechanical system that can create FM signals. It is, in effect, the world's smallest FM radio transmitter.
From the production of tougher, more durable smartphones and other electronic devices, to a wider variety of longer lasting biomedical implants, bulk metallic glasses are poised to be mainstay materials for the 21st Century. Featuring a non-crystalline amorphous structure, bulk metallic glasses can be as strong or stronger than steel, as malleable as plastics, conduct electricity and resist corrosion.
Researchers have made the first battery electrode that heals itself, opening a new and potentially commercially viable path for making the next generation of lithium-ion batteries for electric cars, cell phones and other devices. The secret is a stretchy polymer that coats the electrode, binds it together and spontaneously heals tiny cracks that develop during battery operation.
Sometimes big change comes from small beginnings. That’s especially true in the research of Anatoly Frenkel, a prof. of physics at Yeshiva Univ., who is working to reinvent the way we use and produce energy by unlocking the potential of some of the world’s tiniest structures: nanoparticles.
Stanford Univ. researchers have developed an inexpensive device that uses light to split water into oxygen and clean-burning hydrogen. The goal is to supplement solar cells with hydrogen-powered fuel cells that can generate electricity when the sun isn't shining or demand is high.
The decades-long effort to create practical superconductors moved a step forward with the discovery at Rice Univ. that two distinctly different iron-based compounds share common mechanisms for moving electrons. Samples from two classes of iron-based superconductors, pnictides and chalcogenides, employ similar coupling between electrons in their superconducting state.
Scientists in Japan have recently shown that structural control of small magnetic vortex structures called skyrmions could lead to a compact, low-power alternative to conventional magnetic data storage. Skyrmions occur rarely in certain magnetic compounds, but after it was discovered that they can exist near room temperature and can be manipulated with little current, research interest has grown.
Researchers have created tiny holograms using a metasurface capable of the ultra-efficient control of light, representing a potential new technology for advanced sensors, high-resolution displays and information processing. The metasurface, thousands of V-shaped nanoantennas formed into an ultra-thin gold foil, could make possible optical switches small enough to be integrated into computer chips for information processing.
Univ. of Cambridge scientists have uncovered the mechanism by which bacteria build their surface propellers (flagella). The results demonstrate how the mechanism is powered by the subunits themselves as they link in a chain that is pulled to the flagellum tip. Previously, scientists thought that the building blocks for flagella were either pushed or diffused from the flagellum base.
When you squeeze atoms, you don’t get atom juice. You get magnets. According to a new theory by Rice Univ. scientists, imperfections in certain 2-D materials create the conditions by which nanoscale magnetic fields arise. Calculations by the laboratory of Rice theoretical physicist Boris Yakobson show these imperfections, called grain boundaries, in 2-D semiconducting materials known as dichalcogenides can be magnetic.
Stingrays swim through water with such ease that researchers from the Univ. at Buffalo and Harvard Univ. are studying how their movements could be used to design more agile and fuel-efficient unmanned underwater vehicles. The vehicles could allow researchers to more efficiently study the mostly unexplored ocean depths, and they could also serve during clean up or rescue efforts.
The phonon, like the photon or electron, is a physical particle that travels like waves, representing mechanical vibration. Phonons transmit everyday sound and heat. Recent progress in phononics by a research scientist at Georgia Institute of Technology has led to the development of new ideas and devices that are using phononic properties to control sound and heat, even to the point of freeing bustling city blocks from the noise of traffic.
Superfluidity refers to a state in which matter behaves like a liquid with zero viscosity. With a few exceptions, superfluidity has generally been regarded as a macroscopic phenomenon, resulting from “bulky” collections of particles rather than individual atoms. Scientists in Switzerland have now provided the first experimental evidence of superfluidity at the nanoscale, shedding light on the fundamental basis of the phenomenon.
Semiconductors, the foundation of modern electronics used in flatscreen televisions and fighter jets, could become even more versatile as researchers make headway on a novel, inexpensive way to turn them into thin films. Their report on a new liquid that can quickly dissolve nine types of key semiconductors appears in the Journal of the American Chemical Society.
A new device capable of pumping human waste into the “engine room” of a self-sustaining robot has been created by a group of researchers from Bristol. Modeled on the human heart, the artificial device incorporates smart materials called shape memory alloys and could be used to deliver human urine to future generations of EcoBot—a robot that can function completely on its own by collecting waste and converting it into electricity.
Invisibility cloaking is no longer the stuff of science fiction: Two researchers at the Univ. of Toronto have demonstrated an effective invisibility cloak that is thin, scalable and adaptive to different objects. The team designed and tested a new approach to cloaking—by surrounding an object with small antennas that collectively radiate an electromagnetic field. The radiated field cancels out any waves scattering off the cloaked object.
Tiny electrical wires protrude from some bacteria and contribute to rock and dirt formation. Pacific Northwest National Laboratory researchers studying the protein that makes up one such wire have determined the protein's structure and have shown that the protein's shape and form suggest possible ways for the bacteria to shuttle electrons along the nanowire.
Using the x-ray beams at the European Synchrotron Research Facility a research team has showed that the electrons absorbed and released by cerium dioxide nanoparticles during chemical reactions behave in a completely different way than previously thought. They show that the electrons are not bound to individual atoms but, like a cloud, distribute themselves over the whole nanoparticle, like an electron “sponge".
Despite their almost incomprehensibly small size, single-walled carbon nanotubes come in a plethora of different “species,” each with its own structure and unique combination of electronic and optical properties. Characterizing the structure and properties of an individual carbon nanotube has involved a lot of guesswork, until now.