Posted in materials
Revealing hidden layers in superconducting nickelates.
In a collaborative effort, researchers from the Max Planck Institute for Solid State Research (MPI-FKF) have discovered a new crystal structure in La₃Ni₂O₇, a material known to exhibit high-temperature superconductivity under high pressure.
Inside a hunk of a material called a semimetal, scientists have uncovered signatures of bizarre particles that sometimes move like they have no mass, but at other times move just like a very massive particle.
Astronomers have discovered one of the fastest-spinning neutron stars ever recorded, known as 4U 1820–30, which rotates an astonishing 716 times per second. Located 26,000 light-years away in the Sagittarius constellation, this neutron star is part of an X-ray binary system where its intense gravity pulls material from a companion white dwarf, triggering explosive thermonuclear bursts.
Researchers have developed a novel method using facet-selective, ultrafine cocatalysts to efficiently split water to create hydrogen – a clean source of fuel. Scientists are urgently searching for clean fuel sources – such as hydrogen – to move towards carbon neutrality. A breakthrough for improving the efficiency of the photocatalytic reaction that splits water into hydrogen has been made by a team of researchers from Tohoku University, Tokyo University of Science and Mitsubishi Materials Corporation.
“Water-splitting photocatalysts can produce hydrogen (H2) from only sunlight and water,” explains Professor Yuichi Negishi, the lead researcher of this project (Tohoku University), “However, the process hasn’t been optimized sufficiently for practical applications. If we can improve the activity, hydrogen can be harnessed for the realization of a next-generation energy society.”
The research team established a novel method that uses ultrafine rhodium (Rh)-chromium (Cr) mixed-oxide (Rh2-xCrxO3) cocatalysts (the actual reaction site and a key component to stop H2 reforming with oxygen to make water again) with a particle size of about 1 nm. Then, they are loaded crystal facet-selectively onto a photocatalyst (uses sunlight and water to speed up reactions). Previous studies have not been able to accomplish these two feats in a single reaction: a tiny cocatalyst that can also be placed on specific regions of the photocatalyst.
A lithium-ion battery made from three droplets of hydrogel is the smallest soft battery of its kind – and it could be used in biocompatible and biodegradable implants.
Recently, two independent research groups have shown that the brain codes for zero much as it does for other numbers, on a mental number line. But, one of the studies found, zero also holds a special status in the brain.
In recent years, research started to uncover how the human brain represents numbers, but no one examined how it handles zero. Now two independent studies, led by Nieder and Barnett, respectively, have shown that the brain codes for zero much as it does for other numbers, on a mental number line. But, one of the studies found, zero also holds a special status in the brain.
“The fact that [zero] represents nothing is a contradiction in itself,” said Carlo Semenza, a professor emeritus of neuroscience at the University of Padua in Italy who wasn’t involved in either study. “It looks like it is concrete because people put it on the number line — but then it doesn’t exist. … That is fascinating, absolutely fascinating.”
The new studies are the first to reveal what goes on in the brain when a person thinks about zero, and they bring up broader questions about how the mind handles absence — a pursuit that would have pleased Jean-Paul Sartre, the 20th-century existentialist who claimed that “nothingness carries being in its heart.”
Researchers Tomohito Amano and Shinji Tsuneyuki of the University of Tokyo with Tamio Yamazaki of CURIE (JSR-UTokyo Collaboration Hub) have developed a new machine learning model to predict the dielectric function of materials, rather than calculating from first-principles.
High-temperature superconductivity is one of the great mysteries of modern physics: Some materials conduct electrical current without any resistance—but only at very low temperatures. Finding a material that remains superconducting even at room temperature would spark a technological revolution. People all over the world are therefore working on a better, more comprehensive understanding of such materials.
Researchers at the University of California, Berkeley, have developed a new material for direct air capture that outperforms existing technologies.
This covalent organic framework (COF) can effectively remove carbon dioxide from ambient air, mimicking the absorptive capacity of trees but at a significantly accelerated rate.
Carbon Capture Challenges
Researchers Takuma Nakamura, Kazuki Hashimoto, and Takuro Ideguchi of the Institute for Photon Science and Technology at the University of Tokyo have increased by 100-fold the measurement rate of Raman spectroscopy, a common technique for measuring the “vibrational fingerprint” of molecules in order to identify them.
As the measurement rate has been a major limiting factor, this improvement contributes to advancements in many fields that rely on identifying molecules and cells, such as biomedical diagnostics and material analytics. The findings were published in the journal Ultrafast Science.
Identifying various types of molecules and cells is a crucial step in both basic and applied science. Raman spectroscopy is a widely used measurement technique for this purpose. When a laser beam is projected onto molecules, the light interacts with the vibrations and rotations of molecular bonds, shifting the frequency of the scattering light. The scattering spectra thus measured is a molecule’s unique “vibrational fingerprint.”