Science Daily December 15, 2023 An international team of researchers (Sweden, Norway) performed a prospective life cycle assessment (LCA) of large-scale production of two different sodium-ion battery (SIB) cells with a cradle-to-gate system boundary. The SIB cells modeled have Prussian white cathodes and hard carbon anodes based only on abundant elements and thus constituted potentially preferable options to current lithium-ion battery (LIB) cells from a mineral resource. The functional unit was 1 kWh theoretical electricity storage capacity, and the specific energy density of the cells was 160 Wh/kg. For SIB cell materials, prospective inventory data was obtained from a generic […]
Tag Archives: Materials science
Detecting hidden defects in materials using a single-pixel terahertz sensor
Phys.org November 6, 2023 Existing terahertz inspection systems face throughput and accuracy restrictions due to their limited imaging speed and resolution. Furthermore, machine-vision-based systems using large-pixel-count imaging encounter bottlenecks due to their data storage, transmission, and processing requirements. Researchers at UCLA developed a diffractive sensor that rapidly detects hidden defects/objects within a 3D sample using a single-pixel terahertz detector, eliminating sample scanning or image formation/processing. Using deep-learning-optimized diffractive layers, the diffractive sensor could all-optically probe the 3D structural information of samples by outputting a spectrum, and directly indicated the presence/absence of hidden structures or defects. They experimentally validated this framework […]
First-ever wireless device developed to make magnetism appear in non-magnetic materials
Phys.org October 30, 2023 Magneto-ionics is a unique approach to control magnetism with electric field for low-power memory and spintronic applications. So far, magneto-ionics has been achieved through direct electrical connections to the actuated material. Researchers in Spain have shown that such control can be achieved wirelessly. Without direct wire contact inducing polarization in the conducting material immersed in the electrolyte, promoted wireless bipolar electrochemistry, an alternative pathway to achieve voltage-driven control of magnetism based on the same electrochemical processes involved in direct-contact magneto-ionics. They achieved significant tunability of magnetization for cobalt nitride thin films, including transitions between paramagnetic and […]
Physicists turn pencil lead into metaphorical ‘gold’
Phys.org October 30, 2023 Rhombohedral-stacked multilayer graphene hosts a pair of flat bands touching at zero energy, which should give rise to correlated electron phenomena that can be tuned further by an electric field. An international team of researchers (USA – MIT, Harvard University, Japan) measured electron transport through hexagonal boron nitride-encapsulated pentalayer graphene down to 100 mK and observed a correlated insulating state with resistance at the megaohm level or greater at charge density n = 0 and displacement field D = 0. By increasing D, they observed a Chern insulator state with C = −5 and two other states with C = −3 at a magnetic field […]
The right twist and strain for graphene to form 1D moirés
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 […]
Itinerant magnetism and superconductivity in exotic 2D metals for next-generation quantum devices
Phys.org October 23, 2023 Metallic ferromagnets with strongly interacting electrons often exhibit remarkable electronic phases such as ferromagnetic superconductivity, complex spin textures, and nontrivial topology. A team of researchers in the US (UC Berkeley, Los Alamos National Laboratory) conducted a series of experiments with a new type of layered 2D metal, finding connections in electronic behavior that might potentially be useful for fabricating complex superconducting quantum processors. They discussed the synthesis of a layered magnetic metal NiTa4Se8 (or Ni1/4TaSe2) with a Curie temperature of 58 Kelvin. Magnetization data and density functional theory calculations indicated that the nickel atoms host uniaxial […]
Plant-based materials give ‘life’ to tiny soft robots
Science Daily October 23, 2023 Introducing anisotropic properties, and shape-change programmability to responsive hydrogels promises a host of opportunities in the development of soft robots. An international team of researchers (Canada, Germany) synthesized pH-responsive hydrogel nanocomposites with predetermined microstructural anisotropy, shape-transformation, and self-healing. They were largely composed of zwitterionic monomers and asymmetric cellulose nanocrystals. While the zwitterionic nature of the network imparted both self-healing and cytocompatibility to the hydrogel nanocomposites, the shear-induced alignment of cellulose nanocrystals rendered their anisotropic swelling and mechanical properties. They utilized a cut-and-paste approach to program reversible, and complex deformation into the hydrogels. As a proof-of-concept, […]
Living hydrogel fibers unveiling a new era of sustainable engineered materials
Nanowerk September 27, 2023 A major challenge in creating living materials for functional material design, integrating synthetic biology tools to endow materials with programmable, dynamic, and life-like characteristics, is balancing the tradeoff between structural stability, mechanical performance, and functional programmability. To address this problem researchers in China proposed a sheath–core living hydrogel fiber platform that synergistically integrated living bacteria with hydrogel fibers to achieve both functional diversity and structural and mechanical robustness. The microfluidic spinning was used to produce hydrogel fiber, which offered advantages in both structural and functional designability due to their hierarchical porous architectures that could be tailored […]
Light and sound waves reveal negative pressure
Phys.org September 25, 2023 Pressure is encountered in various fields – atmospheric pressure in meteorology, blood pressure in medicine, etc. Examining the physical properties of materials under a wide range of thermodynamic states is a challenging problem due to the extreme conditions the material must experience. Such temperature and pressure regimes, which result in a change in the refractive index and sound velocity, can be accessed by optoacoustic interactions such as Brillouin–Mandelstam scattering. An international team of researchers (Germany, France, Australia) demonstrated the Brillouin–Mandelstam measurements of nanolitre volumes of liquids in extreme thermodynamic regimes enabled by a fully sealed liquid-core […]
Material would allow users to ‘tune’ windows to block targeted wavelengths of light
Phys.org September 26, 2023 Dual-band electrochromism, the independent modulation of visible and near-infrared light by a single material, is highly desirable for smart windows to enhance the energy efficiency of buildings. Tungsten oxides are commercially important electrochromic materials, exhibiting reversible visible and near-infrared absorption when electrochemically reduced in an electrolyte containing small cations or protons. The presence of structural water in tungsten oxides has been associated with faster electrochromic switching speeds. A team of researchers in the US (North Carolina State University, UT Austin, Vanderbilt University) found that WO3·H2O, a crystalline hydrate, exhibited dual-band electrochromism unlike the anhydrous WO3. Making […]