Archive for the ‘materials’ category: Page 46
Oct 20, 2023
From a five-layer graphene sandwich, a rare electronic state emerges
Posted by Chima Wisdom in categories: materials, physics
Despite its waif-like proportions, scientists have found over the years that graphene is exceptionally strong. And when the material is stacked and twisted in specific contortions, it can take on surprising electronic behavior.
Now, MIT physicists have discovered another surprising property in graphene: When stacked in five layers, in a rhombohedral pattern, graphene takes on a very rare, “multiferroic” state, in which the material exhibits both unconventional magnetism and an exotic type of electronic behavior, which the team has coined ferro-valleytricity.
Oct 17, 2023
Solving quantum mysteries: New insights into 2D semiconductor physics
Posted by Paul Battista in categories: materials, quantum physics
Researchers from Monash University have unlocked fresh insights into the behavior of quantum impurities within materials.
The new, international theoretical study introduces a novel approach known as the “quantum virial expansion,” offering a powerful tool to uncover the complex quantum interactions in two-dimensional semiconductors.
This breakthrough holds potential to reshape our understanding of complex quantum systems and unlock exciting future applications utilizing novel 2D materials.
Oct 16, 2023
Hubble snaps hotbed of high-mass star formation
Posted by Genevieve Klien in category: materials
The rich dust clouds that are responsible for producing these giant stars are blocking the light from Hubble’s view. The star and the jet of material it is emitting are visible near the very center.
“The small, bright orange streak is a cavity in the dust carved out by the ferocity of the jet as it streams towards us. By breaking through its dusty cocoon, the jet reveals light from the protostar, but there is still so much dust that the light is “reddened” to a fiery orange. The massive protostar lies at the very lower-left tip of this cavity,” NASA wrote in a post.
Jet-setting through a star formation hotbed!The glimmering, star-forming region seen in this #HubbleFriday view is called G35.2–0.7N. The spectacular light show is caused by a powerful jet of matter ejecting from a very young star: https://go.nasa.gov/3twrzbE pic.twitter.com/hLEwFDqZCy — Hubble (@NASAHubble) October 13, 2023
Oct 16, 2023
Tiny memory cell withstands extreme temperatures, enables smaller and better semiconductors for microelectronics
Posted by Genevieve Klien in categories: chemistry, materials
Materials scientists at Kiel University and the Fraunhofer Institute for Silicon Technology in Itzehoe (ISIT) have cleared another hurdle in the development and structuring of new materials for next-generation semiconductor devices, such as novel memory cells.
They have shown that ferroelectric aluminum scandium nitride can be scaled down to a few nanometers and can store different states, making it suitable as a nanoswitch. In addition, they have proved aluminum scandium nitride to be a particularly stable and powerful semiconductor material for current technologies based on silicon, silicon carbide and gallium nitride. In contrast to today’s microelectronics, the material can withstand extreme temperatures of up to 1,000°C.
This opens up applications such as information storage or sensors for combustion processes in engines or turbines in both the chemical industry and in the steel industry. The results were published in the journal Advanced Science. The study was part of a research project that brings together basic research in materials development and applications in microelectronics.
Oct 16, 2023
Chiro-optical force observed at the nanoscale
Posted by Paul Battista in categories: materials, nanotechnology
A research group at the Institute for Molecular Science has successfully observed the left and right handedness of material structures at the nanoscale, by illuminating chiral gold nanostructures with circularly polarized light and detecting the optical force acting on a probe near the nanostructures. This result demonstrated that it is possible to analyze the chiral structure of matter at the nanoscale using light.
Chirality describes the property of a material structure not being superimposable onto its mirror image. Since the left and right hands, which are mirror images of each other, do not coincide (they are not the same), they are chiral.
Chiral objects can be distinguished to right-or left-handedness. Many substances that constitute life are chiral, and often only one of either the right-or left-handedness naturally exists. Also, in new functional materials, their chiral nature often plays an important role for the functions.
Oct 14, 2023
New Logic Gates Are a Million Times Faster Than Those in Today’s Chips
Posted by Quinn Sena in categories: computing, materials
Year 2022 face_with_colon_three
When the team fired their ultra-fast laser at a graphene wire strung between two gold electrodes, it produced two different kinds of currents. Some of the electrons excited by the light continued moving in a particular direction once the light was switched off, while others were transient and were only in motion while the light was on. The researchers found that they could control the type of current created by altering the shape of their laser pulses, which was then used as the basis of their logic gate.
Logic gates work by taking two inputs—either 1 or 0—processing them, and providing a single output. The exact processing rules depend on the kind of logic gate implementing them, but for example, an AND gate only outputs a 1 if both its inputs are 1, otherwise it outputs a 0.
Continue reading “New Logic Gates Are a Million Times Faster Than Those in Today’s Chips” »
Oct 14, 2023
SOM-backed Prometheus Materials turns algae-like composite into masonry blocks
Posted by Kelvin Dafiaghor in category: materials
Colorado-based Prometheus Materials has developed masonry blocks from a low-carbon cement-like material grown from micro–algae.
The blocks, which meet the American Society for Testing and Materials (ASTM) standards, were made using an organic cement-like material grown in bioreactors that reproduces itself in ways similar to coral.
“Coral reefs, shells, and even the limestone we use to produce cement today show us that nature has already figured out how to bind minerals together in a strong, clever, and efficient way,” said Prometheus Materials co-founder Wil V Srubar III.
Oct 13, 2023
Detection of the Orbital Hall Effect
Posted by Saúl Morales Rodriguéz in category: materials
Two different experiments on two different transition metals reveal that a current of electron orbital angular momentum flows in response to an electric field.
In the spin Hall effect, an applied electric field drives a current of electron spin in a direction transverse to the field. In a transition metal, theorists predict that an orbital angular momentum (OAM) current can also flow. Now two groups have independently observed this so-called orbital Hall effect (OHE) [1, 2]. These observations supplement one made by a third group earlier this year [3]. Together these demonstrations constitute a step toward the development of “orbitronic” devices based on an electron’s orbital degree of freedom.
For their demonstration, Giacomo Sala of the Swiss Federal Institute of Technology (ETH) in Zurich and his colleagues turned to a phenomenon known as Hanle magnetoresistance. In a conductor, when a magnetic field is applied parallel to the direction of electron OAM, orbital moments should accumulate at the edges of the sample because of the OHE. If instead the field is applied perpendicular to electron OAM, the orbital moments should precess. The orbital moments should then fall out of phase with each other, which boosts the material’s magnetoresistance. The team observed these effects in thin films of manganese [1].
Oct 13, 2023
Electronic waste — more recycling needs to be encouraged
Posted by Chima Wisdom in categories: materials, sustainability
New research conducted by the not-for-profit organisation, Material Focus, has found that half a billion small, cheap electrical everyday items, such as headphones or handheld fans, found their way into landfill in the UK last year.