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.”
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.
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.
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.
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.
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 SAM.gov, 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.
A crystalline reflective coating being considered for future gravitational-wave detectors exhibits peculiar noise features at cryogenic temperatures.
Researchers highlight the potential of cobalt-tin-sulfur in spintronic devices, revealing its capability to reduce energy consumption and heralding a new era in electronics.
A team of researchers has made a significant breakthrough that could revolutionize next-generation electronics by enabling non-volatility, large-scale integration, low power consumption, high speed, and high reliability in spintronic devices.
Details of their findings were published recently in the journal Physical Review B.
X-ray technology plays a vital role in medicine and scientific research, providing non-invasive medical imaging and insight into materials. Recent advancements in X-ray technology enable brighter, more intense beams and imaging of increasingly intricate systems in real-world conditions, like the insides of operating batteries.
To support these advancements, scientists are working to develop X-ray detector materials that can withstand bright, high-energy X-rays—especially those from large X-ray synchrotrons—while maintaining sensitivity and cost-effectiveness.
A team of scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory and their colleagues have demonstrated exceptional performance of a new material for detecting high energy X-ray scattering patterns. With excellent endurance under ultra-high X-ray flux and relatively low cost, the detector material may find wide application in synchrotron-based X-ray research.
