Phys.org October 30, 2023 The formation of one-dimensional moiré patterns is a consequence of an interplay between twist and strain which gives rise to a collapse of the reciprocal space unit cell. An international team of researchers (Spain, Poland) found a simple relation between the two quantities and the material specific Poisson ratio. The induced one-dimensional behavior was characterized by two, usually incommensurate, periodicities. According to the researchers their results offer explanations for the complex patterns of one-dimensional channels observed in low angle twisted bilayer graphene systems and twisted bilayer dichalcogenides. Their findings can be applied to any hexagonal twisted […]
Self-powered flexible multicolor electrochromic devices for information displays
Phys.org October 19, 2023 Researchers in China have proposed a new trilayer film structure for self-powered flexible multicolor EC displays based on self-charging/discharging mechanism. It was assembled by sandwiching an ionic gel film between 2 cathodic nickel hexacyanoferrate (NiHCF) and Prussian blue (PB) nanoparticle films on indium tin oxide substrates, had self-powered color switching films with fast responsive time and high reversibility. Multicolor switching was achieved through a color overlay effect by superimposing the 2 EC films, including green, blue, yellow, and colorless. The patterns could be created by the spray-coating method… read more. Open Access TECHNICAL ARTICLE
Study reveals importance of Earth’s upper atmosphere in geomagnetic storm development
Phys.org October 30, 2023 Both solar wind and ionospheric sources contribute to the magnetotail plasma sheet, but how their contribution changes during a geomagnetic storm is an open question. The source is critical because the plasma sheet properties control the enhancement and decay rate of the ring current, the main cause of the geomagnetic field perturbations that define a geomagnetic storm. An international team of researchers (USA – University of New Hampshire, Lockheed Martin Advanced Technology Center, Harvard-Smithsonian Center for Astrophysics, Japan) used the solar wind composition to track the source and showed that the plasma sheet source changed from […]
Study uncovers giant fluctuation-enhanced phonon magnetic moments in a polar antiferromagnet
Phys.org October 28, 2023 In some non- and paramagnetic systems, a large phonon magnetic moment is found due to coupling with electronic excitations. However, for magnetically ordered systems, a correspondingly large moment has not yet been discovered, and the roles of many-body correlations and fluctuations in phonon magnetism remain unclear. Researchers in China found a phonon magnetic moment that was enhanced by critical fluctuations in Fe2Mo3O8. Combining magneto-Raman spectroscopy and inelastic neutron scattering measurements, they showed that a pair of low-lying chiral phonons carried large magnetic moments. Once the system was driven to a ferrimagnetic phase, they observed a splitting […]
A superatomic semiconductor sets a speed record
Science Daily October 26, 2023 The transport of energy and information in semiconductors is limited by scattering between electronic carriers and lattice phonons, resulting in diffusive and lossy transport that curtails all semiconductor technologies. Researchers at Columbia University used Re6Se8Cl2, a superatomic semiconductor, to demonstrate the formation of acoustic exciton-polarons. They directly imaged polaron transport in Re6Se8Cl2 at room temperature, revealing quasi-ballistic, wavelike propagation sustained for a nanosecond and several micrometers. Shielded polaron transport led to electronic energy propagation lengths orders of magnitude greater than in other vdW semiconductors, exceeding even silicon over a nanosecond. According to the researchers quasi-flat […]
Virtual meetings tire people because we’re doing them wrong, says new research
Phys.org October 30, 2023 Researchers in Finland challenged the commonly held belief that virtual meeting fatigue manifests as exhaustion resulting from overloading demands and instead suggested that participation in virtual meetings may lead to increased drowsiness due to underload of stimulation. Using subjective and cardiac measures they investigated the relationships between virtual versus face-to-face meetings and different types of fatigue (active and passive) among 44 knowledge workers during real-life meetings. Their multilevel path analysis revealed a link between virtual meetings and higher levels of passive fatigue, which then impacted cognitive performance. Their results suggested that work engagement may act as […]
Top 10 Science and Technology Inventions for the Week of October 27, 2023
01. From a five-layer graphene sandwich, a rare electronic state emerges 02. Itinerant magnetism and superconductivity in exotic 2D metals for next-generation quantum devices 03. New noble-metal-free electrocatalyst decreases the energy required to generate hydrogen gas from water 04. Further evidence of Earth’s core leaking found on Baffin Island 05. Plant-based materials give ‘life’ to tiny soft robots 06. Researchers create the most water-repellent surface ever 07. Scientists isolate early-warning tremor pattern in lab-made earthquakes 08. Shape-shifting fiber can produce morphing fabrics 09. Silk nanointerfaces merge biology and electronics 10. A step on the way to solid-state batteries And others […]
3D-printed aluminium alloy with unprecedented fatigue resistance
Nanowerk October 24, 2023 Researchers in France have shown a fatigue resistance phenomenon in nano-TiB2-decorated AlSi10Mg enabled by additive manufacturing. This fatigue resistance mechanism benefited from the three-dimensional dual-phase cellular nanostructure, which acted as a strong volumetric nanocage to prevent localized damage accumulation fatigue crack initiation. The intrinsic fatigue strength limit of nano-TiB2-decorated AlSi10Mg was shown to be close to its tensile strength. They showed that printed bulk nano-TiB2-decorated AlSi10Mg achieved fatigue resistance more than double those of other additive manufacturing Al alloys and surpassed those of high-strength wrought Al alloys. According to the researchers their method can be extended […]
Cathode active materials for lithium-ion batteries could be produced at low temperatures
Science Daily October 23, 2023 Layered LiCoO2 is usually synthesized after a prolonged sintering process at high temperatures for 10–20 h. Researchers in Japan have developed a “hydroflux process” to obtain highly crystalline and layered LiCoO2 at a low temperature within 30 min. They found that the molten mixed hydroxide-containing water molecules significantly accelerated the formation of LiCoO2, which showed a highly reversible capacity of 120 mAh g–1 without post annealing. The reaction mechanism study showed fast growth of LiCoO2 crystals suggesting that the excess molten hydroxides containing water dissolved the cobalt species of HCoO2 and suppressed the competing reaction […]
China’s ‘Great Green Wall’ boosts carbon sink, study finds
Phys.org October 20, 2023 Three-North Afforestation Program (TNAP) in China is the largest ecological restoration project on Earth (ongoing from 1978 to 2050), harboring a huge area of newly planted forests, which provides a wealth of goods and ecosystem services that benefit society in East Asia. This project-induced carbon sink has been expected to be large, but its size and location remain uncertain. An international team of researchers (China, USA – Clemson University) investigated the changes in the C stocks of biomass, soil C and the C accumulation benefited from the ecological effects in the project areas from 1978 to […]