8 ADVANCED MATERIALS & PROCESSES | OCTOBER 2024 devices. The research team employed a novel near-field transient nanoscopy technique to probe the behavior of materials at the nanoscale with both high spatial and temporal resolution. This approach overcomes the limitations of traditional optical methods, allowing researchers to directly visualize and analyze phenomena that were previously difficult to observe. The team focused on atomically thin transition metal dichalcogenides (TMDCs), materials known for their unique optical and electronic properties. They also examined vanadium dioxide (VO2), a material celebrated for its remarkable phase-change properties. Using their advanced imaging techniques, the researchers mapped out the nanoscale distribution of metallic and insulating phases in bent VO2 nanobeams. The team observed slower carrier recombination but faster diffusion in the metallic phase of VO2 compared to its insulating phase. This finding provides new insights into the material’s behavior during phase transitions, which could be crucial for developing advanced switching and memory devices. The research also highlighted the impact of local material properties, such as strain and interfaces, on exciton and carrier dynamics in both TMDCs and VO2. These discoveries have significant implications for the development TESTING | CHARACTERIZATION FASTER IMAGING FOR ATOMIC BEAM MICROSCOPES Researchers at Swansea University created a new imaging method for neutral atomic beam microscopes that could lead to much faster results for engineers and scientists when scanning samples. Existing neutral atomic beam microscopes obtain images by illuminating the sample through a microscopic pinhole. Now, the Swansea researchers developed a new—and faster—alternative method to pinhole scanning. They demonstrated the new method using a beam of helium-3 atoms, a rare light isotope of regular helium. The technique works by passing a beam of atoms through a non- uniform magnetic field and using nuclear spin precession to encode the position of the beam particles, which interact with the sample. The team used numerical simulations to show that the new magnetic encoding method should be capable of improving image resolution with a significantly smaller increase in time. “The method we have developed opens up various new opportunities in the field of neutral beam microscopy,” lead researcher Gil Alexandrowicz says. “In the immediate future, the new method will be further developed to create a fully working prototype magnetic encoding neutral beam microscope. In the more distant future, this new type of microscope should become available to scientists and engineers to characterize the topography and composition of sensitive and delicate samples they produce or study.” www.swansea.ac.uk. A CLOSER LOOK AT ULTRAFAST CARRIER DYNAMICS Scientists are achieving extra- ordinary insights into ultrafast carrier dynamics in advanced materials thanks to cutting- edge nanoscale optical imagining techniques developed by researchers at the University of California, Berkeley. Their work shows significant progress in understanding the carrier behaviors in 2D and phasechange materials, with implications for next-generation electronic and optoelectronic The Giant Magellan Telescope and Ingersoll Machine Tools Inc. have started manufacturing the largest telescope mount ever built in the U.S. Once fully assembled in Rockford, Ill., the mount will undergo testing before being shipped to Chile for reassembly and use by the early 2030s. Magellan will be 200 times more powerful than today’s best telescopes. giantmagellan.org. BRIEF Schematic shows transient s-SNOM, which measures exciton dynamics in MoS2. Courtesy of Advanced Materials, 2024, doi.org/10.1002/adma.202311568. A magnetic encoding device is lifted by a crane before being attached to the beam line. Courtesy of Morgan Lowe.
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