Archive for the ‘materials’ category: Page 6

Oct 11, 2023

Realizing attosecond core-level X-ray spectroscopy for the investigation of condensed matter systems

Posted by in categories: materials, particle physics

The many-body interaction of charges (electrons) and nuclei (phonons) plays a critical role in determining the properties and functionalities of molecules and solids. The exact correlated motion of these particles gives rise to different conductivity, energy storage capabilities, phase transitions, and superconductivity. Now, the team of ICREA Prof. at ICFO Jens Biegert has developed attosecond soft X-ray core-level spectroscopy as a method to observe the correlated interaction between charges and phonons in real time.

Attosecond soft X-ray spectroscopy relies on the use of ultrashort pulses with photon energies that cover the entire water-window range. Through high-order with an intense few-cycle short-wavelength infrared pulse, the team has successfully generated a bright 165 attosecond pulse with photon energies of up to 600 eV. By directing this ultrashort soft X-ray pulse into the sample, the high-energy photons can excite the electrons in the K-shell or L-shell to unoccupied or continuum states.

This soft X-ray absorption spectroscopy provides researchers with a powerful tool for unraveling the electronic and structural characteristics of the material at the same time.

Oct 11, 2023

Researchers realize orientation control of cMOF nanofilms

Posted by in categories: engineering, materials

Researchers from the Institute of Process Engineering (IPE) of the Chinese Academy of Sciences and Kyoto University have proposed a strategy to grow “face-on” and “edge-on” conductive metal-organic frameworks (cMOF) nanofilms on substrates by controlling the “stand-up” behaviors of ligands on various surfaces to overcome the difficulty in the orientation control of such films.

They established operando characterization methodology using and X-ray to demonstrate the softness of the crystalline nanofilms and reveal their unique conductive functions. The study was published in Proceedings of the National Academy of Sciences on Sept. 25.

CMOFs have great potential for use in modern electrical devices due to their porous nature and the ability to conduct charges in a regular network. cMOFs applied in normally hybridize with other materials, especially substrates. Therefore, precisely controlling the between a cMOF and a substrate is crucial.

Oct 11, 2023

Ionic crystal generates molecular ions upon positron irradiation

Posted by in categories: biotech/medical, materials

The positron, the antiparticle of the electron, has the same mass and charge as that of an electron but with the sign flipped for the charge. It is an attractive particle for scientists because the use of positrons has led to important insights and developments in the fields of elementary particle physics, atomic physics, materials science, astrophysics, and medicine.

For instance, positrons are known to be components of antimatter. They are also powerful in detecting lattice defects in solids and semiconductors and in structural analysis of the topmost surface of crystals.

Positronic compounds, namely bound states of positrons with regular atoms, molecules, or ions, represent an intriguing aspect of –matter interactions and have been studied experimentally via observation of positron annihilation in gases. It may be possible to generate new molecules and ions via the formation of positron compounds, but no research has ever been done from such a perspective.

Oct 9, 2023

Invisible Electron ‘Demon’ Discovered in Odd Superconductor

Posted by in categories: materials, physics

Physicists have long suspected that hunks of metal could vibrate in a peculiar way that would be all but invisible. Now physicists have spotted these “demon modes.”

Oct 9, 2023

How to watch NASA reveal the Bennu asteroid sample

Posted by in categories: materials, space

NASA recently succeeded at bringing to Earth a sample collected from a distant asteroid, and this week it will show off the material for the first time.

Oct 9, 2023

Narrower-Energy Electron Pulses without Electron Loss

Posted by in categories: energy, materials

Researchers demonstrate a method to reduce the energy spread of electrons used in electron microscopes, opening the door to time-and energy-resolved studies of quasiparticles such as phonons and plasmons.

Conceived a century ago, electron microscopes are today standard fare in experimental research laboratories. By imaging a material with electrons, scientists can resolve details 1,000 times smaller than is possible with light. These devices can also employ pulsed electron beams to probe transient phenomena, such as the behavior of quasiparticles that a material hosts. Now Michael Yannai of Technion–Israel Institute of Technology and his colleagues demonstrate a way to improve that capability by reducing the energy spread of the electrons in a pulsed imaging beam [1]. Their method leaves the brightness of the beam unchanged, which is important for ultrafast imaging, as the ultrashort pulses used in this method necessarily comprise small numbers of electrons. “Our technique opens the path to many potential time-and energy-resolved explorations that are currently impossible,” says Ido Kaminer, who headed the team behind the research.

Electron energy spread is one of the key factors limiting an electron microscope’s resolution. The smaller this spread—the closer the beam is to being monochromatic—the better the resolution. The conventional method for reducing energy spread is to filter out electrons with energies outside of the desired range. But that process significantly reduces the electron flux, another factor that can limit a microscope’s performance.

Oct 7, 2023

Study show defects passing thorough diamond faster than sound

Posted by in category: materials

The results will help researchers understand phenomena like seismic ruptures and structural failures by understanding how quickly they move.

In the realm of material science, understanding the delicate balance between strength and vulnerability has been a quest that has spanned decades.

Take the case of metals; they are strong and workable because of something known as linear flaws or dislocations. But they can also cause materials to break catastrophically, as happens every time you snap the pull tab off a Coke can.

Oct 5, 2023

“Unusual” Findings Overturn Current Battery Wisdom

Posted by in categories: innovation, materials

Scientists have made a significant breakthrough in understanding and overcoming the challenges associated with Ni-rich cathode materials used in lithium-ion batteries.

While these materials can reach high voltages and capacities, their real-world usage has been limited by structural issues and oxygen depletion.

Their study revealed that ‘oxygen hole’ formation – where an oxygen ion loses an electron — plays a crucial role in the degradation of LiNiO2 cathodes accelerating the release of oxygen which can then further degrade the cathode material.

Oct 5, 2023

NASA wants a ‘lunar freezer’ for its Artemis moon missions

Posted by in categories: materials, space

NASA has issued a request for “lunar freezer” designs that can safely store materials taken from the moon during planned Artemis missions.

According to a request for information (RFI) posted to the federal contracting website, the freezer’s primary use will be transporting scientific and geological samples from the moon to Earth. These samples, the post specifies, will be ones collected during the Artemis program.

Oct 4, 2023

Unexpected Noise in Next-Generation Mirror Material

Posted by in categories: futurism, materials

A crystalline reflective coating being considered for future gravitational-wave detectors exhibits peculiar noise features at cryogenic temperatures.

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