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Tiny water droplets transmutate aniline into pyridine in ambient and catalyst-free conditions

Aniline can now be transformed into pyridine without adding any catalysts, oxidants or toxic reagents. In a recent study published in the Journal of the American Chemical Society, researchers achieved skeletal editing, involving the reorganization of the carbon-nitrogen bonds within an aromatic ring, by turning an aqueous solution of aniline into a mist of microdroplets.

During its millisecond-long airborne lifespan, aniline underwent rapid molecular rearrangement, inserting nitrogen into the aromatic ring and forming pyridine, driven by the uniquely active air-water interface in microdroplets. The green, reagent-free reaction converted up to 80% of the starting material into the product under ambient conditions, eliminating the added energy cost often required to carry out such conversion reactions.

By testing droplets of different sizes, charges and acidity levels, researchers found that the reaction is boosted at the droplet’s interface, a zone that is rich in protons and highly polarized. The smaller the droplet, the larger its reactive surface area relative to its volume, and the better the reaction outcome.

Ultra-fast light-shaping technology could be ‘game-changer’ for future imaging

Scientists have developed a new type of “virtual” metasurface—capable of controlling light in ways traditional lenses and optics can’t—which they say is superior to the current approach, which relies on ultrathin engineered materials. The Nottingham Trent University team says the work will help fully optimize metasurface potential for a range of real-world applications and paves the way for a move from physical to virtual platforms in nanotechnology.

Metasurfaces are many times thinner than a human hair and can bend and focus light, change its color and steer it in different directions, meaning they can replace bulky optical elements in small devices such as lenses, mirrors and filters.

While they are powerful, however, the materials and dimensions of physical metasurfaces are fixed—once built, they can’t change their shape, which can limit how useful they are in real-world technologies.

Nearly isotropic superconducting property revealed in trilayer nickelate

A research team led by Prof. Zhang Jinglei from Hefei Institutes of Physical Science, Chinese Academy of Sciences, found that the trilayer nickelate La4Ni3O10-δ exhibits a nearly isotropic upper critical field under high pressure. This finding provides important experimental insight into the superconducting mechanism of nickel-based materials.

The study is published in Physical Review X.

Since the discovery of superconductivity with a transition temperature (Tc) approaching 80 K under high pressure in the bilayer Ruddlesden–Popper (RP) nickelate La3Ni2O7-δ, bulk superconductivity (Tc≈20 K) has also been verified in single crystals of the trilayer isostructural compound La4Ni3O10-δ under pressure. However, probing its properties remains technically demanding, as experiments must simultaneously achieve ultra-high pressure, strong magnetic fields and cryogenic temperatures.

Agentic AI bot helps scientists speak to robots, speeding up experiments

Researchers at the Department of Energy’s Pacific Northwest National Laboratory use a slew of autonomous robots to design and implement experiments. However, setting up an experiment on an autonomous lab robot is surprisingly slow. The effort requires a lengthy back-and-forth between a scientist and an engineer to design the experimental steps—a process that can take weeks.

To help researchers work more efficiently, a PNNL team developed a generative agentic AI that can quickly translate experimental goals into instructions for a laboratory robot. The translation agent, called AutoLabs, is currently designed to operate with Big Kahuna, an automated robot built by Unchained Labs that researchers use to study new and existing battery materials. The system can carry out multistep experimental workflows, including mixing, heating, stirring and filtering samples with minimal human intervention. By automating these processes, researchers can perform five to 10 times more experiments than would be practical by hand.

The team published a paper in Scientific Reports about AutoLabs, and the software is also available for other researchers to download on GitHub.

Laser experiments push helium to record shock pressures

Deep inside gas giants like Jupiter and Saturn, hydrogen and helium coexist under pressures millions of times greater than Earth’s atmosphere. Under those conditions, helium may separate from hydrogen and influence a planet’s internal heat flow, structure and magnetic field. Understanding these processes and how these materials behave under extreme conditions is essential to building accurate models of planetary evolution.

New experimental results, published in Physical Review Research, reveal the behavior of helium at unprecedented pressures. The research, conducted by scientists at Lawrence Livermore National Laboratory (LLNL), the University of California, Berkeley, the French Commissariat à l’Énergie Atomique et aux Energies Alternatives (CEA) and the University of Rochester’s Laboratory for Laser Energetics (LLE), shows that helium behaves differently from what most broad-range theoretical models predicted.

A magnetic field that kills superconductivity can also bring it back

Magnetic fields are generally known to destroy superconductivity in a material. However, in exceptional cases, they can lead to what is known as “re-entrant superconductivity”—where superconductivity disappears as expected, but then unexpectedly returns when the magnetic field is increased further.

This behavior is sometimes seen in bulk, three-dimensional materials, but now, in a study published in Science Advances, a team led by the RIKEN Center for Emergent Matter Science (CEMS) in Japan has seen the phenomenon in a very thin conducting layer at the boundary between two insulating oxide materials. Because oxide interfaces can be precisely engineered and controlled, the discovery provides a new platform for investigating unconventional forms of superconductivity and the quantum mechanisms that allow it to survive under unusual conditions.

Geometric anti-spring works near absolute zero, suppressing vibrations below 0.185 hertz

Physicists and instrument makers in Leiden have succeeded in optimizing a spring that almost completely filters out vibrations at temperatures near absolute zero. This breakthrough opens the door to a new generation of highly sensitive experiments. The research is published in the journal Measurement Science and Technology.

“Our new special spring reduces the disruptive vibrations down to 0.185 hertz, which is a major improvement,” says Ph.D. candidate Louw Feenstra. Instrument makers Kees van Oosten and Hugo van Bohemen designed and built the new instrument in their workshop and tested it in the lab together with Feenstra.

Today, many—if not all—modern physics experiments are based on extremely precise measurements. Such measurements are often carried out inside a cryostat, a device that cools materials to temperatures as close as possible to absolute zero (0 Kelvin equals −273.15°C). Until now, cryostats had one major drawback: Their cooling systems generate strong vibrations, particularly around 1 hertz—roughly one vibration per second. For sensitive experiments, this can seriously affect the results.

Interlayer self-doping could unlock room-temperature multiferroics in atom-thin materials

Multiferroics are materials that exhibit more than one prominent “ferroic” property, such as ferromagnetism and ferroelectricity. One of their most advantageous features is that they allow engineers to control their magnetic states with electric fields or vice versa, due to an effect known as magnetoelectric coupling.

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