The addition of elements to the surface of graphene can modify the material’s physical and chemical properties, potentially extending the range of possible applications. Recently performed theoretical calculations at RIKEN in Japan show that the addition of oxygen to graphene on copper substrates results in enhanced functionalization. The resulting structure, known as an enolate, make support applications that require catalytic response.
Perovskites continue to entice materials scientists with their mix of conductivity, ferroelectricity, ferromagnetism, and catalytic activity. In recent years, scientists realized that they could vastly improve the properties of perovskites by assembling them into thin films, but nobody knew the reason why. But studying the chemistry layer-by-layer, experts working with x-ray beamline at Argonne National Laboratory are getting close.
Scientists at Stanford Univ. and the Dept. of Energy (DOE)’s SLAC National Accelerator Laboratory have found a way to estimate uncertainties in computer calculations that are widely used to speed the search for new materials for industry, electronics, energy, drug design and a host of other applications. The technique, reported in Science, should quickly be adopted in studies that produce some 30,000 scientific papers per year.
A research group based in Japan has developed a new methodology that can easily and precisely control the timing, structure, and functions in the self-assembly of pi-conjugated molecules, which are an important enabling building block in the field of organic electronics. One of the key steps is keeping these molecules in a liquid form at room temperature.
First developed five years ago at Rice Univ., silicon oxide memories are a type of two-terminal, “resistive random-access memory” (RRAM) technology that beats flash memory’s data density by a factor of 50. At Rice, the laboratory of chemist and 2013 R&D Magazine Scientist of the Year James Tour has recently developed a new version of RRAM that Tour believes outperforms more than a dozen competing versions.
A recent study by researchers at the Univ. of Illinois at Urbana-Champaign provides new insights on the physical mechanisms governing the interplay of spin and heat at the nanoscale, and addresses the fundamental limits of ultra-fast spintronic devices for data storage and information processing.
Too cool and faint, many objects in the universe are impossible to detect with visible light. Now a Northwestern Univ. team has refined a new technology that could make these colder objects more visible, paving the way for enhanced exploration of deep space. The new technology uses a type II superlattice material called indium arsenide/indium arsenide antimonide (InAs/InAsSb).
A new type of catalyst, based on carbon, can facilitate two opposite reactions: electrolysis of water and combustion of hydrogen with oxygen. This bi-functionality, developed by researchers in Germany, is made possible from its construction: manganese-oxide or cobalt-oxide nanoparticles which are embedded in specially modified carbon, then integrated with nitrogen atoms in specific positions.
Researchers at the Univ. of California, Riverside have used a quartz-rich material to fabricate a lithium-ion battery that outperforms the current industry standard by three times. This key material? Sand. Through a heating process with salt and magnesium, the scientists created a porous nano-silicon sponge that greatly increases active surface area.
Overturning conventional wisdom stretching all the way to Leonardo da Vinci, new research from Israel shows that how things break and how things slide are closely interrelated. The breakthrough study marks an important advance in understanding friction and fracture, with implications for describing the mechanics that drive earthquakes.
For the last century, the concept of crystals has been a mainstay of solid-state physics. Crystals are paragons of order; crystalline materials are defined by the repeating patterns their constituent atoms and molecules make. Now physicists have evidence that a new concept should undergird our understanding of most materials: the anticrystal, a theoretical solid that is completely disordered.
Using graphene ribbons just several atoms across, a group of researchers at the Univ. of Wisconsin-Milwaukee has found a novel way to “tune” the material, causing the extremely efficient conductor of electricity to act as a semiconductor. By imaging the ribbons with scanning-tunneling microscopy, researchers have confirmed how narrow the ribbon width must be. Achieving less than 10 nm in width is a big challenge.
Nonlinear optical materials are widely used in laser systems, but they require high light intensity and long propagation to be effective. A team in Germany and Texas has designed a new 400-nm thick nonlinear mirror that delivers frequency-doubled output using input light intensity as small as that of a laser pointer. Compared to traditional nonlinear materials, the new option offers a million times increase in nonlinear optical response.
Ancient Japanese gold leaf artists were truly masters of their craft. An analysis of six of these Japanese paper screens show that these artifacts are gilded with gold leaf that was hand-beaten to the nanometer scale. The study was able to prove this without any damage to the screens through the use of x-ray fluorescence spectroscopy.
Using something called a microchannel heat sink to simulate the warm environment of a working computer, researchers in Malaysia have analyzed three nanofluids for the traits that are important in an effective coolant. The results of their study show that the nanofluids, which are made of metallic nanoparticles that have been added to a liquid, such as water, all performed better than water as coolants, with one mixture standing out.
Known as the “world's longest experiment”, an experiment at the University of Queensland in Australia was famous for taking ten years for a drop of pitch, a black, sticky material, to fall from a funnel. A new test in the U.K. is using a different bitumen, or pitch, which is 30 times less viscous than the Queensland experiment, so that the flow can be seen at a faster rate and hopefully provide more insights.
The light-warping structures known as metamaterials have a new trick in their ever-expanding repertoire. Researchers at NIST have built a silver, glass and chromium nanostructure that can all but stop visible light cold in one direction while giving it a pass in the other. The device could someday play a role in optical information processing and in novel biosensing devices.
Materials science experts in North Carolina and China collaborated on work that drew inspiration from the structure of bones and bamboo. The team has found that by gradually changing the internal structure of metals, stronger, tougher materials can be created and customized for a wide variety of applications, from body armor to automobile parts. The gradient structure concept works on numerous metals, including stainless steel and nickel.
Whenever there is a major spill of oil into water, the two tend to mix into a suspension of tiny droplets, called an emulsion, that is extremely hard to separate and can cause severe damage to ecosystems. A new membrane developed by Massachusetts Institute of Technology researchers can separate even these highly mixed fine oil-spill residues.
Using a scanning tunneling microscope to visualize the electronic structure of the oxygen sites within a superconductor, a Binghamton Univ. physicist and his colleagues say they have unlocked one key mystery surrounding high-temperature superconductivity. The team found a density wave with a d-orbital structure, which is a pattern new to this type of superconductor and they may be found in all cuprates.
Researchers at Lawrence Berkeley National Lab and the Univ. of Hawaii have uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and other carbon-based compounds. The finding could help combustion chemists make more-efficient, less-polluting fuels and help materials scientists fine-tune their carbon nanotubes and graphene sheets for faster, smaller electronics.
Recent research at the Rice Univ. lab of materials scientist Pulickel Ajayan has discovered that nanotubes that hit a target end first turn into mostly ragged clumps of atoms. But nanotubes that happen to broadside the target unzip into handy ribbons that can be used in composite materials for strength and applications that take advantage of their desirable electrical properties.
Physicists in Europe have solved a mystery that has puzzled scientists for half a century. it has long been known that the distance between the graphene oxide layers depends on the humidity, not the actual amount of water added. But now, with the help of powerful microscopes, it can be seen how distance between graphite oxide layers gradually increases when water molecules are added, and why this phenomenon occurs.
Researchers in Germany have produced a new material the size of a sugar cube that has a surface area equivalent to more than seven tennis courts. This novel type of nanofiber has a highly ordered and porous structure gives it an extraordinarily high surface-to-volume ratio and could be a key enabling technology for lithium-sulfur batteries.
A group of researchers from Russia, Belarus and Spain, including MIPT professor Yury Lozovik, have developed a microscopic force sensor based on carbon nanotubes. The device consists of two nanotubes placed so that their open ends are opposite to each other. Voltage of just 10 nA is then applied to the nanocircuit and force is measured by the change in position of the nanotubes.