Phys.org December 17, 2024 When the geometrical size of a nanomagnetic system is constricted to the limiting domain wall length scale, the competing energetics between anisotropy, exchange, and dipolar interactions can cause emergent kinetics due to quasiparticle relaxation, like bulk magnets of atomic origin. A team of researchers in the US (Columbia University, Oak Ridge National Laboratory) conducted an experimental and theoretical study to support that constricted nanomagnets, made of antiferromagnetic and paramagnetic neodymium thin film with honeycomb motif, revealed fast kinetic events at picosecond timescales due to the relaxation of topological quasiparticles that persisted to low temperature in the […]
Wind alters snow crystals, impacting climate models
Phys.org December 16, 2024 Loose surface snow gets eroded and transported by wind, which influences the snow particles’ physical properties that determine the characteristics of the emerging wind-impacted snowpack layer. Researchers in Switzerland used cold-laboratory ring wind tunnel experiments to study the governing processes during airborne snow transport with stable water isotopes as tracers for these micro-scale processes. They documented the growing and rounding of snow particles with transport time, with a concurrent decrease in specific surface area and attributed this evolution to the process of airborne snow metamorphism. The changes showed a clear isotopic signature of metamorphic deposition, which […]
Top 10 Science and Technology Inventions for the Week of December 13, 2024
01. Particle that only has mass when moving in one direction observed for first time 02. A new catalyst can turn methane into something useful 03. New third class of magnetism could transform digital memory: Experiment bridges theory and real-life realization 04. Rethinking the quantum chip: Engineers present new design for superconducting quantum processor 05. Room-temperature nanodevice that generates structured light shows promise for secure communication and advanced optics 06. Space-time crystals, an important step toward new optical materials 07. Straining a material’s atomic arrangement may make for cleaner, smarter devices 08. Tuning skyrmion helicity for racetrack memory and quantum […]
3D scans of giant hailstones reveal surprising discoveries that could help predict future storms
Phys.org December 4, 2024 Researchers in Spain analyzed the stones collected during fieldwork to gather information on their growth processes. They analysed used Computed Tomography Scan, which was utilized to analyze hailstones and their interiors. They obtained a complete 3D view of the interior of the stone, without producing any alteration in the structure they quantified densities of different layers. The analysis helped verify previous theories that the nuclei can be placed far from the stone center even if the hailstone is externally spherical… read more. Open Access TECHNICAL ARTICLE
A connection between quantum theory and information theory proved
EurekAlert December 6, 2024 Wave-particle duality is one of the most notable and counterintuitive features of quantum mechanics, illustrating that two incompatible observables cannot be measured simultaneously with arbitrary precision. An international team of researchers (Sweden, Chile, Poland) experimentally demonstrated the equivalence of wave particle duality and entropic uncertainty relations using orbital angular momentum states of light. Their experiment used a reconfigurable platform composed of a few-mode optical results providing fundamental insights into the complementary principle from an informational perspective, with implications for the broader field of quantum technologies… read more. Open Access TECHNICAL ARTICLE
Engineers develop gel-based stretchable triboelectric nanogenerators for wearable technology
Phys.org December 9, 2024 Gel-based sensors typically depend on a metal grid connection, which is susceptible to structural deformation under heavy stress applications and necessitates external power. Researchers in South Korea developed gel polymer electrode-based triboelectric nanogenerator (GPE-TENG) that was stretchable, semi-transparent, and durable, designed to enable a self-powered touch panel for intelligent touch perception. The ionic polymer gel encapsulated within the ecoflex ensured robust adhesion of the ionic conductive polymer gel (PEO/LiTFSI) to the ecoflex layers. It demonstrated high durability, enduring stretching of approximately 375 % and sustaining heavy mechanical deformations over a long period without loss of functionality. […]
Less is more: Why an economical iridium catalyst works so well
Phys.org December 6, 2024 An international team of researchers (Germany, Spain) investigated the electronic and structural behavior of the newly developed oxygen evolution reaction (OER) Kopernikus P2X amorphous IrOx/TiO2. It was compared to the current commercial benchmark catalyst: crystalline IrO2/TiO2, Umicore Elyst. Analysis of the redox behavior of the catalysts showed distinct electronic differences between the amorphous and crystalline oxides. They derived property–structure relationships under equivalent OER conditions for materials exhibiting distinctly different activities and found that P2X IrOx/TiO2 catalyst underwent substantial electronic structure changes, with larger reduction in the Ir–O bond lengths compared to that of the commercial benchmark […]
A new catalyst can turn methane into something useful
MIT News December 4, 2024 Anthropogenic methane emissions, particularly from diffuse and dilute sources, pose a significant challenge for oxidation and valorization as existing methane oxidation routes rely on high temperatures or pressures. Researchers at MIT found that the catalytic coupling of alcohol oxidase with the iron-modified ZSM-5 (Fe-ZSM-5) zeolite catalyst, created a tandem methanotrophic system that partially oxidized methane at ambient temperatures and pressures. They showed that methane-to-formaldehyde selectivity could exceed 90% at room temperature. The generated formaldehyde was rapidly incorporated into a growing urea polymer. According to the researchers their work presents a sustainable route for methane oxidation… […]
New third class of magnetism could transform digital memory: Experiment bridges theory and real-life realization
Phys.org December 11, 2024 The presence of net magnetization limits device scalability and compatibility with phases, such as superconductors and topological insulators. Altermagnetism has been proposed as a solution to these restrictions combined with the antiferromagnetic-like vanishing net magnetization. So far, altermagnetic ordering has been inferred from spatially averaged probes. An international team of researchers (UK, Switzerland, Czech Republic, Germany) demonstrated nanoscale imaging of altermagnetic states from 100-nanometre-scale vortices and domain walls to 10-micrometre-scale single-domain states in manganese telluride. They combined the time-reversal-symmetry-breaking sensitivity of X-ray magnetic circular dichroism with magnetic linear dichroism to achieve maps of the local altermagnetic […]
Particle that only has mass when moving in one direction observed for first time
Phys.org December 10, 2024 In two dimensions, a peculiar class of fermions that are massless in one direction and massive in the perpendicular direction was predicted 16 years ago. The semi-Dirac fermions remain undetected. An international team of researchers (USA – Columbia University, Pennsylvania State University, Florida State University, National High Magnetic Field Laboratory, Harvard University, Temple University, Princeton University, Flatiron Institute, the Netherlands, Spain) demonstrated the defining feature of semi-Dirac fermions in a prototypical nodal-line metal ZrSiS. Their nodal lines extended the band degeneracies from isolated points to lines, loops, or even chains in the momentum space. They pinpointed […]