research briefs professor of materials science and mechanical and aerospace engineering at Missouri S&T and lead author of the new research, says in a Missouri S&T press release. The UCLA–Missouri S&T team has found a way around these past problems, using its technique to achieve a uniform distribution of silicon carbide nanoparticles in a magnesium–zinc alloy. The scientists started with a low concentration of nanoparticles, adding just 1% by volume silicon carbide nanoparticles into the molten alloy. Evaporating the alloy within a vacuum furnace concentrated the nanoparticles, resulting in a final composition of ~14% by volume silicon carbide and ~86% magnesium, the team reports in Nature. “The evenly dispersed nanoparticles provide strength throughout the metal and improve plasticity simultaneously,” Chen says in the Missouri S&T press release. According to the UCLA release, homogenously distributed silicon carbide gives the metal record specific strength and specific modulus, and the metal nanocomposite retains excellent stability under high temperatures, too. But how and why did the nanoparticles distribute so evenly, when this problem has persistently plagued other researchers? The authors hypothesize the process evenly disperses nanoparticles because of three reasons, they write in the paper’s methods. “The self-stabilization of dispersed SiC nanoparticles in magnesium melt is attributed to a synergy of reduced van der Waals forces between Research News the nanoparticles in molten magnesium, a high thermal energy of the nanoparticles, and a high energy barrier preventing nanoparticles from sintering owing to a reasonable wettability between nanoparticles and molten magnesium.” In addition to improving metal’s strength and plasticity, the researchers say their new technique is scalable, although this work is only the beginning. “Although the method reported here is scalable in principle, many efforts are still needed to realize large-volume manufacturing from practical applications,” Chen says in the Missouri S&T release. The research paper, published in Nature, is “Processing and properties of magnesium containing a dense uniform dispersion of nanoparticles” (DOI: 10.1038/nature16445). n Graphene and glass pair up to create robust electronic material that is scalable Scientists at the United States Department of Energy’s Brookhaven National Laboratory, Stony Brook University, and SUNY Polytechnic Institute developed a simple and powerful method for creating resilient, customized, and high-performing graphene: layering it on top of soda– lime glass. “We believe that this work could significantly advance the development of truly scalable graphene technologies,” Matthew Eisaman, study coauthor and physicist at Brookhaven and professor at Stony Brook, says in a Brookhaven news release. The sodium inside the soda–lime glass creates high electron density in the graphene, which is essential to many processes and has been challenging to achieve, coauthor Nanditha Dissanayake of Voxtel Inc. (formerly of Brookhaven) explains in the release. The study, published in Scientific Reports, is “Spontaneous and strong multi-layer graphene n-doping on soda– lime glass and its application in graphene semiconductor junctions” (DOI: 10.1038/srep21070). But the headlines do not stop at the partnership between graphene and glass. Graphene is a metal that behaves similar to water. Researchers at Harvard University recently found that “when the strongly interacting particles in graphene were driven by an electric field, they behaved not like individual particles but like a fluid that could be described by New option manipulates interfaces in metal oxide sandwiches Using a synchrotron to investigate a sandwich system of transitionmetal oxides, Helmholtz-Zentrum Berlin (Germany) scientists have discovered a new option to control properties of the interface between sandwich layers. The scientists investigated charge transfer between samples consisting of gadolinium titanate and rare-earth nickelate films. Their results show that charge transfer at the interface between the oxides strongly depends on the rare-earth element in the nickelate layer. The insights might help create new properties at the interface and even novel forms of high-temperature superconductivity. For more information, visit helmholtz-berlin.de. Riddle of cement’s structure is finally solved An international team of researchers has solved the riddle of cement hydrate (calcium silicate hydrate, CSH) and identified key factors in its structure that could help researchers produce more durable concrete. One key question was whether solidified CSH, which is composed of particles of various sizes, should be considered a continuous matrix or an assembly of discrete particles. The answer is both—particle distribution is such that space between grains is filled by yet smaller grains, to the point that it approximates a continuous solid. The new simulations are the first that can adequately match sometimes conflicting results from CSH experiments. For more information, visit news.mit.edu. 14 www.ceramics.org | American Ceramic Society Bulletin, Vol. 95, No. 3 Credit: FW:Thinking; YouTube Illustration of the molecular structure of graphene.
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