Science Highlights

Relaxor ferroelectrics have greatly enhanced electrical and mechanical properties that originate in the materials’ domain structure. Knowing how quickly these materials’ properties can change is critical to understanding them. However, scientists have not been able to measure how fast these materials can respond. This study measured this reaction speed using ultrafast electron diffraction at the atomic level to obtain snapshots of the evolving domain structure.

Plasmas for fusion research can be heated using neutral beam injection (NBI). With NBI, fast neutral particles from a beam source are injected into the plasma then ionized so that the particles can transfer energy to existing plasma electrons and ions. This transfers the ions’ energy and heats the plasma. Researchers recently studied the variation in electron temperature during NBI and used the data to experimentally determine the neutral beam deposition profile.

Researchers have shown that a novel memristor device consisting of metal, dielectric, and metal layers remembers the history of electrical signals sent through it. The interface between metal and dielectric in the novel device is critical for stable switching and enhanced performance. Simulations indicate that circuits built on this device exhibit improved image recognition.

In oilseed crops like canola, yellow-seeded varieties generally produce more oil than brown-seeded varieties. Camelina, a bioenergy crop closely related to canola, usually has brown seeds. Scientists have now disrupted genes called TT8 that are responsible for making seeds brown, producing an engineered camelina with light yellow seeds that accumulates more than 20% more oil than ordinary varieties.

Pockets of instability called magnetic islands in the plasma in a fusion device can disrupt plasma confinement. Scientists predict that islands grow because of the temperatures of electrons and ions in a plasma flattening out within the island, but ion temperatures have not been previously measured. In this new research, researchers found that contrary to expectations, the ion temperature profile did not flatten but instead exhibited a steep change across islands.

One of the methods scientists use to study quantum many-body systems is the ab initio approach, but some ab initio methods run into severe computational problems when using realistic interactions. This study introduces wavefunction matching and uses it to perform lattice simulations with realistic interactions. This allows scientists to make calculations that were once impossible.

Researchers have developed a way to consistently produce 17-4 PH stainless steel using additive manufacturing, or 3D printing. The rapid change in temperatures that occur in these materials after they are heated by the lasers in 3D printers make it difficult to achieve the toughness needed for 17-4 PH steel. This research used bright X-ray beams to observe those fast changes in real time, then altered the chemical composition to compensate for them.