Science Alert January 30, 2023 An international team of researchers (Italy, University of South Florida, Caltech, Princeton University) report the discovery of a dodecagonal quasicrystal Mn72.3Si15.6Cr9.7Al1.8Ni0.6—composed of a periodic stacking of atomic planes with quasiperiodic translational order and 12-fold symmetry along the two directions perpendicular to the planes. They found it in a fulgurite consisting predominantly of fused and melted sand along with traces of melted conductor metal from a nearby downed power line. According to the researcher fulgurite may have been created by a lightning strike that combined sand with material from downed power line or from electrical discharges from the downed power line alone. It reached temperatures of at least 1,710 °C as indicated by the […]
Tag Archives: Materials science
GHz burst mode femtosecond laser pulses can create unique two-dimensional periodic surface nanostructures
Phys.org January 24, 2023 Most studies using the GHz burst mode femtosecond laser pulses focus on ablation of materials to achieve high-efficiency and high-quality material removal. Researchers in Japan explored the ability of the GHz burst mode femtosecond laser processing to form laser-induced periodic surface structures (LIPSS) on silicon. The direction of LIPSS formed by the single-pulse mode with linearly polarized laser pulses is typically perpendicular to the laser polarization direction. They showed that the GHz burst mode femtosecond laser created unique two-dimensional LIPSS. The team has proposed a possible mechanism for the formation of 2D LIPSS formed by the […]
Scientists unveil least costly carbon capture system to date
Science Daily January 23, 2023 Rigorous process modeling and techno-economic analyses are limited for emerging carbon capture technologies. A team of researchers in the US (PNNL, industry, Washington State University) has developed four CO2-Binding Organic Liquids (CO2BOLs), all water-lean solvents, as promising options towards energy-effective and low-cost carbon capture from point sources. CO2BOLs can capture up to 97–99% CO2 from coal fired plant. The estimated carbon capture cost is about 12–23% less expensive than the conventional aqueous amine technology. In addition to vapor liquid equilibrium and kinetics (key properties for aqueous solvents), viscosity, volatility, and hydrophobicity, also have strong impacts […]
Blocking radio waves and electromagnetic interference with the flip of a switch
Phys.org January 16, 2023 Foam materials can adjust the reflection and absorption of microwaves, enabling a tunable electromagnetic interference shielding capability. But their thickness of several millimetres hinders their application in integrated electronics. Researchers at Drexel University have developed a method for modulating the reflection and absorption of incident electromagnetic waves using various submicrometre-thick MXene thin films. The reversible tunability of electromagnetic interference shielding effectiveness was realized by electrochemically driven ion intercalation and de-intercalation; this resulted in charge transfer efficiency with different electrolytes, accompanied by expansion and shrinkage of the MXene layer spacing. They demonstrated an irreversible electromagnetic interference shielding […]
Researchers gain deeper understanding of mechanism behind superconductors
Phys.org January 17, 2023 High-temperature superconducting cuprates respond to doping with a dome-like dependence of their critical temperature (Tc). But the family-specific maximum Tc can be surpassed by application of pressure. Researchers in Germany investigated the phenomenon with high-pressure anvil cell NMR and measured the charge content at planar Cu and O, and with it the doping of the CuO2. They found that pressure increases the overall hole doping but when it enhances Tc above what can be achieved by doping, pressure leads to a hole redistribution favoring planar O. This is similar to the observation that the family-specific maximum […]
Discovery of a new form of carbon called long-range ordered porous carbon
Phys.org January 11, 2023 Carbon structures with covalent bonds connecting C60 molecules have been reported but until now there was no process to produce large enough quantities for detailed characterization and exploration necessary for potential applications. An international team of researchers (China, South Korea) has developed a gram-scale preparation method for long-range ordered porous carbon (LOPC), from C60 powder catalysed by α-Li3N at ambient pressure. LOPC consists of connected broken C60 cages that maintain long-range periodicity. At a lower temperature, shorter annealing time or by using less α-Li3N polymerized C60 crystal forms due to the electron transfer from α-Li3N to […]
Electrons take new shape inside unconventional metal
Phys.org January 10, 2023 After an extensive study of the angular dependence of quantum oscillations (QOs) in the electrical conductivity of YPtBi an international team of researchers (USA – University of Maryland, Missouri University of Science and Technology, Rutgers University, Canada) has reported an anomalous Shubnikov–de Haas effect consistent with the presence of a coherent j=3/2 Fermi surface. The QO signal in YPtBi manifested an extreme anisotropy upon rotation of the magnetic field from the [100] to [110] crystallographic direction, where the QO amplitude vanished. According to the researchers this radical anisotropy for such a highly isotropic system cannot be […]
‘Smart’ coating can be precisely applied to make fabric into protective gear
Science Daily January 9, 2023 Previously a team of researchers in the US (Dartmouth University, Maine University, DEVCOM Aberdeen Proving Ground) had developed conductive metal-organic technology (framework) which was a simple coating that could be layered onto cotton and polyester to create smart fabrics. In their current work, instead of the simple coating they precisely embedded the framework into fabrics using a copper precursor that allowed them to create specific patterns and more effectively fill in the tiny gaps and holes between threads. They found that the framework technology effectively converted the toxin nitric oxide into nitrite and nitrate, and […]
At the edge of graphene-based electronics
Nanowerk December 22, 2022 An international team of researchers (USA – Georgia Institute of Technology, National High Magnetic Field Laboratory, France) has demonstrated that the annealed edges in conventionally patterned graphene epitaxially grown on a silicon carbide substrate (epigraphene) are stabilized by the substrate and support a protected edge state. The edge state has a mean free path that is greater than 50 microns, 5000 times greater than the bulk states and involves a theoretically unexpected Majorana-like zero-energy non-degenerate quasiparticle that does not produce a Hall voltage. In seamless integrated structures, the edge state formed a zero-energy one-dimensional ballistic network […]
Nanostructure strengthens, de-ices, and monitors aircraft wings, wind turbine blades, and bridges
Phys.org December 22, 2022 Researchers in Russia have developed nanostructured sensor made of carbon nanotubes which generates heat under electrical current. When it is embedded in a composite, it leaves the composite’s thickness unaffected, other characteristics unimpaired and does not create undesirable pores. It can serve as a sensor for structural health monitoring or a heater for anti-icing or de-icing purposes. By applying an electrical current to the carbon nanotube layer and monitoring the signal, it is possible to keep track of the structure’s deterioration and avert disaster by anticipating breakage. Electricity can also be used for heating to de-ice […]