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Archive for the ‘materials’ category: Page 21

Jun 18, 2024

Strange metal state discovered in hydrogen-rich compound of lanthanum under pressure

Posted by in category: materials

Researchers from Skoltech, Jilin University and Beijing HPSTAR in China, and their German colleagues have synthesized and studied a new type of hydrogen-rich superconductor. Technically referred to as an A15-type lanthanum superhydride, with the formula La4H23, it shows superconductivity below minus 168 degrees Celsius at a pressure of 1.2 million atmospheres. The research results were published in the National Science Review.

Polyhydrides are a novel class of compounds synthesized at about 1 million times the normal atmospheric pressure on Earth. They can exhibit unique superconducting properties with record-high critical temperatures of up to-23 C in lanthanum decahydride LaH10, critical magnetic fields reaching 300 tesla, and critical current densities.

Even compared to other similar hydrides, the newly discovered La4H23 behaves unusually: It has a negative temperature coefficient of electrical resistance in a certain pressure range. That is, unlike ordinary metals, with a decrease in temperature its electrical resistance does not decrease but grows, the way it happens in semiconductors and many unconventional superconductors, such as cuprates.

Jun 17, 2024

New crack-resistant cement material inspired by nature

Posted by in category: materials

Inspired by the materials found in oyster and abalone shells, engineers at Princeton have developed a groundbreaking cement material.

Jun 16, 2024

New 3D printing technique integrates electronics into microchannels to create flexible, stretchable microfluidic devices

Posted by in categories: 3D printing, materials

The transition from traditional 2D to 3D microfluidic structures is a significant advancement in microfluidics, offering benefits in scientific and industrial applications. These 3D systems improve throughput through parallel operation, and soft elastomeric networks, when filled with conductive materials like liquid metal, allowing for the integration of microfluidics and electronics.

Jun 16, 2024

Using Wobbling Stellar Material, astronomers measure the Spin of a Supermassive Black Hole for the first time

Posted by in categories: cosmology, materials

Astronomers at MIT, NASA, and elsewhere have a new way to measure how fast a black hole spins, by using the wobbly aftermath from its stellar feasting.

The method takes advantage of a black hole tidal disruption event—a blazingly bright moment when a black hole exerts tides on a passing star and rips it to shreds. As the star is disrupted by the black hole’s immense tidal forces, half of the star is blown away, while the other half is flung around the black hole, generating an intensely hot accretion disk of rotating stellar material.

The MIT-led team has shown that the wobble of the newly created accretion disk is key to working out the central black hole’s inherent spin.

Jun 14, 2024

Counterfeit Titanium Found In Some Boeing And Airbus Jets

Posted by in categories: materials, transportation

So what else is faked material and what is structural integrity in the world of fakes?


“The planes that included components made with the material were built between 2019 and 2023, among them some Boeing 737 Max…”

Jun 14, 2024

Temperature-Dependent Excitonic Light Manipulation with Atomically Thin Optical Elements

Posted by in category: materials

Monolayer 2D semiconductors, such as WS2, exhibit uniquely strong light–matter interactions due to exciton resonances that enable atomically thin optical elements. Similar to geometry-dependent plasmon and Mie resonances, these intrinsic material resonances offer coherent and tunable light scattering. Thus far, the impact of the excitons’ temporal dynamics on the performance of such excitonic metasurfaces remains unexplored. Here, we show how the excitonic decay rates dictate the focusing efficiency of an atomically thin lens carved directly out of exfoliated monolayer WS2. By isolating the coherent exciton radiation from the incoherent background in the focus of the lens, we obtain a direct measure of the role of exciton radiation in wavefront shaping. Furthermore, we investigate the influence of exciton–phonon scattering by characterizing the focusing efficiency as a function of temperature, demonstrating an increased optical efficiency at cryogenic temperatures. Our results provide valuable insights into the role of excitonic light scattering in 2D nanophotonic devices.

Jun 13, 2024

Data as the next challenge in atomistic machine learning

Posted by in categories: materials, robotics/AI

As machine learning models are becoming mainstream tools for molecular and materials research, there is an urgent need to improve the nature, quality, and accessibility of atomistic data. In turn, there are opportunities for a new generation of generally applicable datasets and distillable models.

Jun 12, 2024

New theory links quantum geometry to electron-phonon coupling

Posted by in categories: materials, quantum physics

A new study published in Nature Physics introduces a theory of electron-phonon coupling that is affected by the quantum geometry of the electronic wavefunctions.

The movement of electrons in a lattice and their interactions with the lattice vibrations (or phonons) play a pivotal role in phenomena like superconductivity (resistance-free conductivity).

Electron-phonon coupling (EPC) is the interaction between free electrons and phonons, which are quasiparticles representing the vibrations of a crystal lattice. EPC leads to the formation of Cooper pairs (pairs of electrons), responsible for superconductivity in certain materials.

Jun 12, 2024

Researchers leverage inkjet printing to make a portable multispectral 3D camera

Posted by in categories: materials, robotics/AI

Researchers have used inkjet printing to create a compact multispectral version of a light field camera. The camera, which fits in the palm of the hand, could be useful for many applications including autonomous driving, classification of recycled materials and remote sensing.

Jun 12, 2024

Researchers unveil the dynamical nature of emergent magnetic monopoles in real magnets for the first time

Posted by in category: materials

Recently, researchers discovered that a material called manganese germanide (MnGe) has a unique periodic structure, formed by special magnetic configurations called hedgehogs and antihedgehogs, which is called a magnetic lattice.

In these special configurations, the point radially outward (hedgehog) or inward (antihedgehog), resembling the spines of a hedgehog. These hedgehogs and antihedgehogs act like and antimonopoles, serving as sources or sinks of emergent magnetic fields.

MnGe exhibits what is known as a triple-Q hedgehog lattice. However, recent experiments have shown that the substitution of Ge with Si (MnSi1-x Gex) transforms the arrangement into the quadruple-Q hedgehog lattice (4Q-HL).

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