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 […]
Tag Archives: Materials science
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 […]
Team creates protein-based material that can stop supersonic impacts
Phys.org December 13, 2022 Extreme energy dissipating materials are essential for a range of applications, in the military, law enforcement, aerospace industry to name a few. Researchers in the UK have created and patented a new shock-absorbing material that could revolutionize both the defense and planetary science sectors. They incorporated a recombinant form of the mechanosensitive protein talin into a monomeric unit and crosslinked, resulting in the production of a talin shock absorbing material (TSAM). When subjected to 1.5 km/s supersonic shots, TSAMs were shown not only to absorb the impact, but to capture/preserve the projectile. According to the researchers […]
Antiferromagnets are suitable for transporting spin waves over long distances, study finds
Phys.org December 6, 2022 In antiferromagnets, the efficient transport of spin-waves has until now only been observed in the insulating antiferromagnet hematite, where circularly polarized spin-waves diffuse over long distances. An international team of researchers (Germany, France, Norway, China) observed long-distance spin-transport in the antiferromagnetic orthoferrite YFeO3, where a different transport mechanism was enabled by the combined presence of the Dzyaloshinskii-Moriya interaction and externally applied fields. The magnon decay length exceeded hundreds of nanometers, in line with resonance measurements that highlight the low magnetic damping. They observed a strong anisotropy in the magnon decay lengths which they attributed to the […]
Iron for energy storage
Max-Plank Society December 2, 2022 The combustion of iron powders seems very promising for stable and high-density energy storage technology. To better understand their in-process morphological and microstructural evolution an international team of researchers (Germany, the Netherlands) investigated two iron powder combustion pathways, one in air and one with the assistance of a propane pilot flame. Both processes resulted in spherical hollow particles composed of a complex microstructure of wüstite, magnetite and/or hematite. They observed nanoparticles on the micro-sized combustion products which indicated partial evaporation. According to the researchers the associated gas production inside the liquid droplet could be the […]