Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: materials

The hexatic phase: Ultra-thin 2D materials in a state between solid and liquid observed for the first time

When ice melts into water, it happens quickly, with the transition from solid to liquid being immediate. However, very thin materials do not adhere to these rules. Instead, an unusual state between solid and liquid arises: the hexatic phase. Researchers at the University of Vienna have now succeeded in directly observing this exotic phase in an atomically thin crystal.

Using state-of-the-art electron microscopy and neural networks, they filmed a silver iodide crystal protected by graphene as it melted. Ultra-thin, two-dimensional materials enabled researchers to directly observe atomic-scale melting processes. The new findings significantly advance the understanding of these phase transitions. Surprisingly, the observations contradict previous predictions—a result now published in Science.

The sudden transition in melting ice is typical of the melting behavior of all three-dimensional materials, from metals and minerals to frozen drinks. However, when a material becomes so thin that it is practically two-dimensional, the rules of melting change dramatically. Between the solid and liquid phases, a new, exotic intermediate phase of matter can arise, known as the “hexatic phase.”

Close-up images show how stars explode in real time

Astronomers have captured images of two stellar explosions—known as novae—within days of their eruption and in unprecedented detail. The breakthrough provides direct evidence that these explosions are more complex than previously thought, with multiple outflows of material and, in some cases, dramatic delays in the ejection process.

The international study, published in the journal Nature Astronomy, used a cutting-edge technique called interferometry at the Center for High Angular Resolution Astronomy (CHARA Array) in California. This approach allowed scientists to combine the light from multiple telescopes, achieving the sharp resolution needed to directly image the rapidly evolving explosions.

“The images give us a close-up view of how material is ejected away from the star during the explosion,” said Georgia State’s Gail Schaefer, director of the CHARA Array. “Catching these transient events requires flexibility to adapt our nighttime schedule as new targets of opportunity are discovered.”

Free radicals caught in the act with slow spectroscopy

Why does plastic turn brittle and paint fade when exposed to the sun for long periods? Scientists have long known that such organic photodegradation occurs due to the sun’s energy generating free radicals: molecules that have lost an electron to sunlight-induced ionization and have been left with an unpaired one, making them very eager to react with other molecules in the environment. However, the exact mechanisms for how and why the energy from the sun’s photons get stored and released in the materials over very long periods have eluded empirical evidence.

The problem lies in the timeframe. While scientists have access to extremely sophisticated spectroscopy equipment capable of measuring the energy levels of individual electrons at femtosecond to millisecond scales in organic materials, they have paid little attention to time scales beyond seconds—and these are processes that can take years.

As such, slow, transient charge accumulation has presented a disappointing data gap in both applied and theoretical optics. But now, researchers from the Organic Optoelectronics Unit at the Okinawa Institute of Science and Technology (OIST) have addressed this challenge with a new methodology that detects these faint signals. Their findings are published in Science Advances.

Intellexa Leaks Reveal Zero-Days and Ads-Based Vector for Predator Spyware Delivery

A human rights lawyer from Pakistan’s Balochistan province received a suspicious link on WhatsApp from an unknown number, marking the first time a civil society member in the country was targeted by Intellexa’s Predator spyware, Amnesty International said in a report.

The link, the non-profit organization said, is a “Predator attack attempt based on the technical behaviour of the infection server, and on specific characteristics of the one-time infection link which were consistent with previously observed Predator 1-click links.” Pakistan has dismissed the allegations, stating “there is not an iota of truth in it.”

The findings come from a new joint investigation published in collaboration with Israeli newspaper Haaretz, Greek news site Inside Story, and Swiss tech site Inside IT. It’s based on documents and other materials leaked from the company, including internal documents, sales and marketing material, and training videos.

Moisture-driven power generator delivers stable electricity even in dry air conditions

Their findings have been published in the journal Advanced Functional Materials in an article titled “Long-Lasting Moisture Energy Scavenging in Dry Ambient Air Empowered by a Salt Concentration-Gradient Cationic Hydrogel.”

How the new MEG technology works These moisture-activated generators (or MEGs) work by creating a flow of ions—charged particles—inside a special gel, generating power naturally. But current versions face challenges: they don’t last long (less than 16 hours), have high internal resistance, and only work well in very humid conditions.

Professor Shin and his team have overcome those hurdles. They developed a salt-concentration-gradient cationic hydrogel for MEG, promising lower energy loss and higher output even in conditions of low relative humidity.

Magnetism switching in antiferromagnets: Two distinct mechanisms successfully visualized

A research team led by Ryo Shimano of the University of Tokyo has successfully visualized two distinct mechanisms through which up and down spins, inherent properties of electrons, switch in an antiferromagnet, a material in which spin alignments cancel each other out. One of the visualized mechanisms provides a working principle for developing ultrafast, non-volatile magnetic memory and logic devices, which could be much faster than today’s technologies.

The findings are published in the journal Nature Materials.

Paper slips with holes, small metal rods, vacuum tubes, and transistors: These are technologies that have been used to encode 0s and 1s, the basis of classical computation. However, the world’s ever-growing computational needs demand yet more powerful tools. Antiferromagnets are a class of materials whose magnetic properties, or lack thereof, could be leveraged to encode 0s and 1s in a novel way.

Scientists Create 7 Remarkable New Ceramic Materials by Simply Removing Oxygen

Sometimes, less truly is more. By removing oxygen during the synthesis process, a team of materials scientists at Penn State successfully created seven new high-entropy oxides (HEOs)—a class of ceramics made from five or more metals that show promise for use in energy storage, electronics, and protective coatings.

“By carefully removing oxygen from the atmosphere of the tube furnace during synthesis, we stabilized two metals, iron and manganese, into the ceramics that would not otherwise stabilize in the ambient atmosphere,” said corresponding and first author Saeed Almishal, research professor at Penn State working under Jon-Paul Maria, Dorothy Pate Enright Professor of Materials Science.

Almishal first succeeded in stabilizing a manganese-and iron-containing compound by precisely controlling oxygen levels in a material he called J52, composed of magnesium, cobalt, nickel, manganese, and iron. Building on this, he used newly developed machine learning tools—an artificial intelligence technique capable of screening thousands of possible material combinations within seconds—to identify six additional metal combinations capable of forming stable HEOs.

Penn State scientists discovered seven new ceramics by simply removing oxygen—opening a path to materials once beyond reach.

During their experiments, the researchers also established a framework for designing future materials based on thermodynamic principles. Their findings were published in Nature Communications.

Smart material instantly changes colors on demand for use in textiles and consumer products

Scientists have developed a revolutionary technique for creating colors that can change on command. These are structural colors that don’t rely on dyes or pigments and can be used for display signage, adaptive camouflage and smart safety labels, among other applications.

Structural colors are not created by pigments or dyes but are colorless arrangements of physical nanostructures. When light waves hit these nanostructures, they interfere with one another. Some waves cancel each other out (they are absorbed) while the rest are reflected (or scattered) back to our eyes, giving us the color we see.

Structural color systems can be engineered to reflect multiple colors from the same colorless material. This is different from pigments, which absorb light and reflect only one color—red pigments reflect red, blue pigments reflect blue and so on.

Euclid dataset of a million galaxies proves connection between galaxy mergers and AGN

Astronomers have long debated the role of galaxy mergers in powering active supermassive black holes. Now an unprecedented dataset of a million galaxies from the Euclid telescope provides evidence that mergers play a dominant role and are even the primary trigger for the most luminous black holes.

Almost all massive galaxies harbor a supermassive black hole (SMBH) at their centers. Most of them simply lurk in the dark while quietly reeling in gas, dust and stars from their surroundings. These materials gather in the black hole’s accretion disk before their irreversible dive into the abyss, thereby emitting the only slight hint of radiation that gives away the black hole’s location.

A small fraction of galaxies possess an SMBH that shines brightly or even pushes out material from its poles. These are called active galactic nuclei (AGN). Some astronomers have hypothesized that violent collisions between galaxies may play an important role in the ignition of AGN. The resulting turbulence could cause the extra material to pile up in an SMBH’s accretion disk, where friction and compression make it hot enough to shine brightly. In the most extreme cases, the AGN are so bright that they completely outshine their host galaxies.

/* */