Physorg March 5, 2018 An international team of researchers (USA – MIT, Harvard University, Japan) created a “superlattice” of two graphene sheets stacked together at a “magic angle” of 1.1 degrees creating a precise moiré configuration. They found that at the magic angle, the two sheets of graphene exhibit nonconducting behavior similar to Mott insulators. When they applied voltage by adding small amounts of electrons to the graphene superlattice, at a certain level, the electrons broke out of the initial insulating state and flowed without resistance, as if through a superconductor. The finding provides a platform for investigating unconventional superconductivity, […]
Tag Archives: Materials science
New technology may protect troops from blast-induced brain injury
Science Daily February 26, 2018 Researchers at the University of Maryland developed highly advanced shock absorber designs that incorporate polyurea-coated tubes and other structures to reduce the blast acceleration experienced by vehicle occupants by up to 80 percent. It spreads out the application of force. Polyurea is compressible and rebounds following compression, resulting in an excellent ability to decrease the acceleration. The research has produced new insights into the causes of TBI experienced by vehicle occupants, even in the absence of significant pressure changes… read more. Open Access TECHNICAL ARTICLE
Many colors from a single dot
Science Daily February 19, 2018 The mechanism underlying the tunable emission appears to be very much dependent on the internal structure of the carbon dots, which differs amongst various preparation techniques. An international team of researchers (the Netherlands, China) studied the emission of individual carbon dots and compared it to the emission of the whole sample and showed that the emission colour of the individual carbon dots can be tuned from blue to red by changing the excitation wavelength, suggesting that multiple colour sites are present and active within a single nanoparticle. These findings demonstrate that it is viable to […]
Scientists test new material for neurocomputers
Physorg February 12, 2018 Bipolar effect of resistive switching (BERS) can be used for developing nonvolatile two-terminal memory cells, as well as for memristors. Researchers in Russia have shown that epitaxial fields that form on the surface of a single-crystalline substrate of strontium titanate can be used to create memristors for a new generation of computers. The innovation in this research is in applying the lithography which allows developing the technology for miniaturization of resistive memory elements…read more. TECHNICAL ARTICLE
Precision experiments reveal gaps in van der Waals theory
Science Daily February 16, 2018 An international team of researchers (Denmark, Japan) measured a single TiS2 crystal to show that the interlayer interactions are in fact stronger than theory indicates, and involve significant electron sharing. The outstanding agreement of the synchrotron diffraction data with theoretical calculations in describing the intralayer Ti-S interactions, supports the validity of these new-found differences for the long-range interactions across the interlayer gaps. The research contributes to the fundamental understanding of weak chemical bonding in 2D layered materials in general, and to the development of TMD materials… read more. TECHNICAL ARTICLE
Compound could transform energy storage for large grids
Phys org February 5, 2018 A team of researchers in the US (University of Rochester, State University of New York – Buffalo) developed a method to modify polyoxometalates by replacing the compound’s methanol-derived methoxide groups with ethanol-based ethoxide ligands. They expanded the potential window during which the cluster was stable, doubling the amount of electrical energy that could be stored in the battery. The ethoxide and methoxide clusters can be generated by using methanol and ethanol. Both reagents are inexpensive, readily available and safe to use. According to the researchers the process may set a new standard in the field… […]
Vanadium dioxyde: A revolutionary material for tomorrow’s electronics
EurekAlert February 5, 2018 An international team of researchers (Switzerland, Germany) working on the EU Horizon 2020 project called Phase-Change Switch found that the atomic structure of the metal-insulator vanadium dioxide (VO2) changes as the temperature rises, transitioning from a crystalline structure at room temperature to a metallic one at temperatures above 68°C. They found that adding germanium to VO2 film can lift the material’s phase change temperature to over 100°C required for modern electronic devices. The technology is particularly effective in the frequency range crucial for space communication systems (the Ka band, with programmable frequency modulation between 28.2 and […]
Controlling quantum interactions in a single material
Science Daily February 5, 2018 Using computational simulations, an international team of researchers (USA – Northwestern University, Austria, Germany, China) discovered coexisting quantum-mechanical interactions in the compound silver-bismuth-oxide. Bismuth enables the spin of the electron to interact with its own motion and does not exhibit inversion symmetry. By applying an electric field to the material, researchers were able to control whether the electron spins were coupled in pairs or separated as well as whether the system is electrically conductive or not. The findings could enable ultrafast, low-power electronics and quantum computers that operate faster than current models… read more. Open Access […]
High-temperature superconductivity gets agile (w/video)
Nanotechweb January 12, 2018 An international team of researchers (Japan, Australia) has synthesized of YBa2Cu3O x superconducting nanorods using solution chemistry. Initially, a mixture of fine-grained coprecipitated powder was obtained and subsequently converted to YBa2Cu3O x nanorods by heating to 1223 K in oxygen for 12 h. The nanorods are superconducting without the need for any further sintering or oxygenation, thereby providing an avenue for direct application to substrates at room temperature or direct use as formed nanorods. The research opens a route to designer superconductors, tailoring them for specific uses… read more. TECHNICAL ARTICLE
A major step forward in organic electronics
Eurekalert January 11, 2018 Researchers in Sweden have shown that ladder-type polymers, such as poly(benzimidazobenzophenanthroline) (BBL), can successfully work as stable and efficient n-channel material for OECTs. BBL-based OECTs show high transconductance (up to 9.7 mS) and excellent stability in ambient and aqueous media. They have demonstrated that BBL-based n-type OECTs can be successfully integrated with p-type OECTs to form electrochemical complementary inverters. The latter show high gains and large worst-case noise margin at a supply voltage below 0.6 V. Applications of the organic components include logic circuits that can be printed on textile or paper, various types of cheap […]