Archive for the ‘materials’ category: Page 4

Sep 1, 2023

Energy Vault’s First Grid-Scale Gravity Energy Storage System Is Near Complete

Posted by in categories: energy, materials, robotics/AI

The system is like a solid version of pumped hydro, which uses surplus generating capacity to pump water uphill into a reservoir. When the water’s released it flows down through turbines, making them spin and generate energy.

Energy Vault’s solid gravity system uses huge, heavy blocks made of concrete and composite material and lifts them up in the air with a mechanical crane. The cranes are powered by excess energy from the grid, which might be created on very sunny or windy days when there’s not a lot of demand. The blocks are suspended at elevation until supply starts to fall short of demand, and when they’re lowered down their weight pulls cables that spin turbines and generate electricity.

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Sep 1, 2023

New 2.5-dimensional structures observed in twisted graphite hybrids

Posted by in categories: materials, particle physics

When two sheets of graphene are placed on top of each other and slightly twisted, their atoms form a moiré pattern, or superlattice. At the so-called “magic” twist angle of 1.08°, something unusual happens: the weak van der Waals (vdW) coupling between atoms in adjacent layers modifies the atoms’ electronic states and transforms the material from a semimetal to a superconductor. The study of such twist-related electronic effects is known as “twistronics”, and it also includes phenomena such as correlated insulator states that appear at different degrees of misalignment.

Because the moiré pattern that underlies twistronics appears only at the interface between two thin sheets, it was assumed that twistronic effects could only occur in structures containing just a few layers. Although it is possible to produce a moiré pattern at a two-dimensional interface within a three-dimensional structure, it was thought that this pattern would not substantially modify the properties of the bulk material. After all, the 2D moiré region would only comprise a small fraction of the total 3D crystal volume.

New work by two research groups – one at the University of Washington in the US and Osaka University in Japan, the other at the University of Manchester in the UK – shows that this picture is not always correct. In fact, rotating a single layer of a 2D material by a small twist angle within a three-dimensional graphite film can cause the properties of the moiré interface to become inextricably mixed with those of the graphite. The result is a new class of hybrid 2D-3D moiré materials that substantially alters our understanding of how twistronics works.

Aug 31, 2023

Demon Hunting: Strange 67-Year-Old Particle Physics Prediction Finally Confirmed

Posted by in categories: materials, particle physics

67 years after its theoretical prediction by David Pines, the elusive “demon” particle, a massless and neutral entity in solids, has been detected in strontium ruthenate, underscoring the value of innovative research approaches.

In 1956, theoretical physicist David Pines predicted that electrons in a solid can do something strange. Although electrons typically have a mass and an electric charge, Pines asserted that they could combine to create a composite particle that is massless, neutral, and doesn’t interact with light. He named this theoretical particle a “demon.” Since then, it has been theorized to play an important role in the behaviors of a wide variety of metals. Unfortunately, the same properties that make it interesting have allowed it to elude detection since its prediction.

Fast forward 67 years, and a research team led by Peter Abbamonte, a professor of physics at the University of Illinois Urbana-Champaign (UIUC), has finally found Pines’ elusive demon. As the researchers report in the journal Nature, they used a nonstandard experimental technique that directly excites a material’s electronic modes, allowing them to see the demon’s signature in the metal strontium ruthenate.

Aug 31, 2023

LIBS confirms the presence of Sulphur (S) on the lunar surface through unambiguous in-situ measurements

Posted by in category: materials

The Laser-Induced Breakdown Spectroscopy (LIBS) instrument onboard Chandrayaan-3 Rover has made the first-ever in-situ measurements on the elemental composition of the lunar surface near the south pole. These in-situ measurements confirm the presence of Sulphur (S) in the region unambiguously, something that was not feasible by the instruments onboard the orbiters.

LIBS is a scientific technique that analyzes the composition of materials by exposing them to intense laser pulses. A high-energy laser pulse is focused onto the surface of a material, such as a rock or soil. The laser pulse generates an extremely hot and localized plasma. The collected plasma light is spectrally resolved and detected by detectors such as Charge Coupled Devices. Since each element emits a characteristic set of wavelengths of light when it’s in a plasma state, the elemental composition of the material is determined.

Preliminary analyses, graphically represented, have unveiled the presence of Aluminum (Al), Sulphur (S), Calcium (Ca), Iron (Fe), Chromium (Cr), and Titanium (Ti) on the lunar surface. Further measurements have revealed the presence of manganese (Mn), silicon (Si), and oxygen (O). Thorough investigation regarding the presence of Hydrogen is underway.

Aug 30, 2023

Biopolymer Photonics: From Nature to Nanotechnology

Posted by in categories: materials, nanotechnology

Simple heterojunction combines many functions in a single component.

Aug 28, 2023

Scientists discover strange ‘singularities’ responsible for exotic type of superconductivity

Posted by in category: materials

Superconductors that work at temperatures much higher than absolute zero have befuddled scientists since they were discovered. A new theory might be about to change that.

Aug 28, 2023

Discovery puts a magnetic spin on neuromorphic computing

Posted by in categories: computing, materials

The word “fractals” might inspire images of psychedelic colors spiraling into infinity in a computer animation. An invisible, but powerful and useful, version of this phenomenon exists in the realm of dynamic magnetic fractal networks.

Dustin Gilbert, assistant professor in the Department of Materials Science and Engineering, and colleagues have published new findings in the behavior of these networks—observations that could advance neuromorphic computing capabilities.

Their research is detailed in their article “Skyrmion-Excited Spin-Wave Fractal Networks,” cover story for the August 17, 2023, issue of Advanced Materials.

Aug 28, 2023

A Hidden State Between Liquid And Solid May Have Been Found

Posted by in categories: materials, particle physics

Glass might look and feel like a perfectly ordered solid, but up close its chaotic arrangement of particles more closely resemble the tumultuous mess of a freefalling liquid frozen in time.

Known as amorphous solids, materials in this state defy easy explanation. New research involving computation and simulation is yielding clues. In particular, it suggests that, somewhere in between liquid and solid states is a kind of rearrangement we didn’t know existed.

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Aug 28, 2023

Clean Power Breakthrough: “Impossible” Energy Generation Using Graphene Challenges Century-Old Physics Paradigms

Posted by in categories: materials, particle physics

A team of researchers reports they have succeeded in disproving a long-held tenet of modern physics–that useful work cannot be obtained from random thermal fluctuations–thanks in part to the unique properties of graphene.

The microscopic motion of particles within a fluid, otherwise known as Brownian motion for its discovery by Scottish scientist Robert Brown, has long been considered an impossible means of attempting to generate useful work.

The idea had been most famously laid to rest decades ago by physicist Richard Feynman, who proposed a thought experiment in May 1962 involving an apparent perpetual motion machine, dubbed a Brownian ratchet.

Aug 26, 2023

Physicists synthesize single-crystalline iron in the form likely found in Earth’s core

Posted by in categories: materials, physics

A team of physicists and geologists at CEA DAM-DIF and Universit´e Paris-Saclay, working with a colleague from ESRF, BP220, F-38043 Grenoble Cedex and another from the European Synchrotron Radiation Facility, has succeeded in synthesizing a single-crystalline iron in a form that iron has in the Earth’s core.

In their published in the journal Physical Review Letters, the group describes how they used an experimental approach to synthesize pure single-crystalline ε-iron and possible uses for the material.

In trying to understand Earth’s internal composition, scientists have had to rely mostly on seismological data. Such studies have led scientists to believe that the core is solid and that it is surrounded by liquid. But questions have remained. For example, back in the 1980s, studies revealed that seismic waves travel faster through the Earth when traveling pole to pole versed equator to equator, and no one could explain why.

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