EPFL researchers have developed a method to calibrate electron spectrometers with extreme accuracy by linking microwave, optical, and free-electron frequencies.

Frequency is one of the most precisely measurable quantities in science. Thanks to optical frequency combs, tools that generate a series of equally spaced, precise frequencies like the teeth of a ruler, researchers can connect frequencies across the electromagnetic spectrum, from microwaves to optical light, enabling breakthroughs in timekeeping, spectroscopy, and navigation.

Electron energy-loss spectroscopy (EELS) is a powerful tool used to investigate the structure and properties of materials at the atomic level. It works by measuring how electrons lose energy as they pass through a sample. But although EELS provides excellent spatial resolution, its spectral resolution, the ability to measure energy precisely, has lagged behind optical methods.

Non-destructive testing allows engineers to evaluate the integrity of structures such as pipelines, tanks, bridges, and machinery without dismantling them. Conventional approaches rely on loudspeakers, lasers, or electric sparks. While effective, these systems can be difficult or dangerous to use in flammable or confined areas and require considerable power to function effectively.

Now, a new study from Japan, available online in Measurement, shows how a common packaging material can replace power-hungry devices in non-destructive testing. The team, led by Professor Naoki Hosoya, along with Shuichi Yahagi from Tokyo City University, Toshiki Shimizu and Seiya Inadera from the Shibaura Institute of Technology, and Itsuro Kajiwara of Hokkaido University, found a simple way to test pipes for hidden flaws by using bubble wrap.

The researchers discovered that the sharp crack of a bubble burst can be a viable substitute for the expensive, energy-dependent tools usually employed in non-destructive testing. The researchers claim the method can detect objects inside a pipe within a 2% error margin, without requiring electricity or heavy equipment.

An international team led by researchers at MPI-CPfS used irradiation with extremely high-energy electrons to controllably introduce atomic defects in superconducting nickelate thin films. Their systematic investigation recently published in Physical Review Letters helps to narrow down the possible answers to fundamental questions of how superconductivity emerges in these materials.

Superconductors are materials that completely expel magnetic fields and perfectly transmit electrical current without any losses, properties which make them both fascinating playgrounds to probe fundamental physical understanding of materials as well as potentially revolutionary technological building blocks.

Some kinds of superconductors are relatively well-understood, explained by theoretical models developed starting in the 1950s. Other classes of superconductors remain more mysterious, but can exhibit superconductivity at higher temperatures, making them more attractive for practical applications.

Scientists have developed a chromium-molybdenum-silicon alloy that withstands extreme heat while remaining ductile and oxidation-resistant. It could replace nickel-based superalloys, which are limited to about 1,100°C. The new material might make turbines and engines significantly more efficient, marking a major step toward cleaner, more powerful energy systems.