Nanowerk August 1, 2023 Laser slicing is a technique of slicing materials along cracks formed by scanning a focused ultrashort-pulse laser beam inside the materials. Researchers in Japan proposed a novel slicing technique to fabricate diamond wafers and demonstrate slicing at the {100} surface. Cracks parallel to the {100} plane are needed to fabricate the wafer. However, crystal materials contain a cleavage plane at the {111} plane, which cracks easily. Typically, cracks propagate not only along the {100} plane, which was the intended slicing plane, but also along the {111} plane, which increased the kerf loss. To restrict these undesirable […]
Tag Archives: S&T Japan
Insights into designing advanced stimuli-responsive porous materials
Phys.org July 21, 2023 MOFs which possess a high degree of crystallinity and a large surface area with tunable inorganic nodes and organic linkers. The adsorption in MOFs changes the crystalline structure and elastic moduli. Thus, the coexistence of adsorbed/desorbed sites makes the host matrices elastically heterogeneous. To show the asymmetric role of elastic heterogeneity in the adsorption–desorption transition researchers in Japan constructed a minimal model incorporating adsorption-induced lattice expansion/contraction and an increase/decrease in the elastic moduli. They found that the transition was hindered by the entropic and energetic effects which become asymmetric in the adsorption process and desorption process, […]
Novel thermal sensor could help drive down the heat
Science Daily July 24, 2023 Excess heat from electronic or mechanical devices is a sign or cause of inefficient performance. In many cases, embedded sensors to monitor the flow of heat could help engineers alter electronic or mechanical devices behavior or designs to improve their efficiency. Researchers in Japan explored the way a heat flux sensor consisting of certain special magnetic materials and electrodes behaves when there are complex patterns of heat flow. They etched desired patterns into the resultant film, similar to how electronic circuits are made. They designed the circuits in a particular kind of way to boost […]
Researchers use liquid crystals that mimic beetle shell coloration units to create a more secure type of QR code
Phys.org July 14, 2023 Cholesteric liquid crystals (CLCs) are becoming increasingly popular due to their unique chiral structural color. Unlike ordinary CLCs materials, CLCs particles exhibit angle-independence, making them particularly noteworthy. However, currently, there are limited effective methods for controlling the structural color of CLCs particles, other than adjusting the concentration of chiral dopants or introducing stimuli-responsive groups. Researchers in Japan have developed a scalable and cost-effective process for preparing monodisperse CLCs particles via dispersion polymerization. By making CLCs into micrometer-sized monodisperse spheres, the helical pitch of CLCs could be varied according to its particle size, and the resulting structural […]
New material shows promise for next-generation memory technology
Nanowerk July 10, 2023 Phase change memory could potentially revolutionize data storage because of its high storage density, and faster read and write capabilities. But still, the complex switching mechanism and intricate fabrication methods associated with these materials have posed challenges for mass production. Unlike conventional amorphous-crystalline PCMs, NbTe4 demonstrates both a low melting point and a high crystallization temperature. This unique combination offers reduced reset energies and improved thermal stability at the amorphous phase. Researchers in Japan fabricated NbTe4 and evaluated its switching performance. It exhibited a significant reduction in operation energy compared to conventional phase-change memory compounds. The […]
Supercomputer used to simulate winds that cause clear air turbulence
Science Daily July 12, 2023 Although clear air turbulence (CAT) generation in the free atmosphere has been studied by high-resolution numerical simulations, few studies simulated aircraft-scale turbulence eddies and validated them with high-frequency airborne observation. Researchers in Japan used a regional numerical weather prediction model to simulate the event with fine resolution. They compared the onboard-recorded data with the virtual flight data, to confirm that turbulent eddies were reasonably reproduced. The CAT was largely generated by breaking Kelvin-Helmholtz (KH) instability waves in the free atmosphere. They resolved the KH waves and their breaking. When the resolution was finer, the turbulent […]
Magnetic bacteria point the way
Science Daily June 27, 2023 Magnetotactic bacteria contain magnetosomes, iron crystals wrapped in a membrane, which arrange themselves to align with the Earth’s magnetic field, causing the bacteria to travel in the direction of Earth’s magnetic field lines leading north or south. Magnetosome-producing microorganisms can sense and move toward the redox gradient. Researchers in Japan collected a deep-sea hydrothermal vent chimney. The mineralogical and geochemical characterization of the vent chimney sample showed an internal iron redox gradient. The electron microscopy of particles collected from the chimney sample revealed magnetotactic bacteria (MTB) cells with bullet-shaped magnetosomes, and there were minor occurrences […]
Nanosheet technology developed to boost energy storage dielectric capacitors
Science Daily July 4, 2023 Dielectric capacitors can become ideal, safe energy storage devices. However, they yield rather low energy densities compared with other energy storage devices such as batteries and supercapacitors. Researchers in Japan designed ultrahigh energy storage capacitors using two-dimensional (2D) high-κ dielectric perovskites (Ca2Nam–3NbmO3m+1; m = 3–6). Individual Ca2Nam–3NbmO3m+1 nanosheets exhibited an ultrahigh dielectric strength even in the monolayer form, which exceeded those of conventional dielectric materials. Multilayer stacked nanosheet capacitors exhibited ultrahigh energy densities, high efficiencies (>90%), excellent reliability (>107 cycles), and temperature stability (−50–300 °C); the maximum energy density was much higher than those of […]
Researchers discover materials exhibiting huge magnetoresistance
Nanowerk June 9, 2023 Much of the hardware and sensors electronic devices rely on magnetoresistive random access memory (MRAM) and magnetic sensors. In magnetoresistive devices when the magnets are aligned, electrons can easily tunnel through the thin insulating barrier between them making the device efficient; when magnets are not aligned the device is less efficient due to higher resistance. Current tunnel magnetoresistive devices comprise magnesium oxide and iron-based magnetic alloys, like iron-cobalt. Iron-based alloys have a body-centered cubic crystal structure in ambient conditions and exhibit a huge tunnel magnetoresistance effect in devices with a rock salt-type magnesium oxide. Researchers in […]
Unveiling the nanoscale frontier: Innovating with nanoporous model electrodes
Phys.org June 2, 2023 Researchers in Japan have fabricated the next-generation membrane electrodes for fundamental electrochemical research of amorphous-based porous carbon materials by the uniform carbon coating of anodic aluminum oxide formed on an Al substrate and free from a barrier layer. The conformally carbon-coated layer formed vertically aligned giant carbon nanotubes, and their walls comprised low-crystalline stacked graphene sheets. The diameter and the length of the nanopores could be tuned over a broad range of between 10 to 200 nm and 2 to 90 µm, respectively. Unlike composite electrodes made from other ordered nanoporous carbons, this model electrode exhibited […]