April AMP_Digital

A D V A N C E D M A T E R I A L S & P R O C E S S E S | A P R I L 2 0 1 9 9 chemical conditions, enabling it to con- tinually corrode and deteriorate over time. The discovery capped a years- long effort to capture chemical compo- sition measurements and images at the atomic scale in 3D using APT. “This study sets a new precedent for characterizing this important redox interface,” says PNNL Laboratory Fel- low Kevin Rosso, adding that the re- sults can be used to better understand a broad range of processes. These in- clude understanding how crystals grow and dissolve, and also the underlying causes of corrosion and how it creates rust on surfaces. pnnl.gov. far more flexible and less brittle than current state-of-the-art ceramic aero- gels—it can be compressed to 5% of its original volume and fully recover as opposed to a compression threshold of 20% in existing aerogels. The new ma- terial is made of thin layers of boron nitride, a ceramic, with atoms that are connected in hexagonal patterns. In the current research study, the new aerogel withstood conditions that would typically fracture other aerogels. It stood up to hundreds of exposures to sudden and extreme temperature NEW ULTRA-LIGHTWEIGHT CERAMIC AEROGEL Researchers from UCLA, in col- laboration with eight other research institutions, developed an extremely light and durable ceramic aerogel. The material could be used for applications like insulating spacecraft because it can withstand the intense heat and severe temperature changes inherent in space missions. Ceramic aerogels have been used to insulate industrial equipment since the 1990s, as well as to insulate scientific equipment on NASA’s Mars rover missions. But the UCLA team’s new version is much more durable after exposure to extreme heat and repeat- ed temperature spikes, and also much lighter. In addition, its unique atomic composition and microscopic structure make it unusually elastic. When heated, the material con- tracts rather than expanding like oth- er ceramics. It also contracts perpen- dicularly to the direction that it is com- pressed. As a result, the material is Using iron isotopes and APT, scientists created the first 3D atomic maps of the rearrangement of different iron atoms in a small iron oxide crystal. A new ceramic aerogel is so lightweight that it can rest on a flower without dam- aging it. Courtesy of UCLA. spikes, which the researchers attribute to its unique architecture. ucla.edu .