Close-up visualizations of (A) the HOMO and (B) LUMO single-particle electron states in the 64CaO glass. Both states are spin-degenerate, and h1 labels the cavity (cage) occupied by LUMO. Yellow and magenta stand for different signs of the wave-function nodes. (C) Simulation box and the electron spin-density of the 64CaO glass with one oxygen subtracted at h2—that is, with two additional electrons. The two electrons have the same spin and they occupy separate cavities, h1 (boundary, also shown in B) and h2 (center, location of removed oxygen), which are separated by 12 Å from each other. (D) Cage structure around the spin-density of one electron cor- responding to the h2 cavity (close-up from C). Al, gray; Ca, green; O, red. (Photo : Argonne National Laboratory)
Alchemy is still alive and thriving, at least for one group of scientists who have managed to turn liquid cement into liquid metal. The process could lead to new manufacturing techniques in electronics.
"This new material has lots of applications, including as thin-film resistors used in liquid-crystal displays, basically the flat panel computer monitor that you are probably reading this from at the moment," said physicist Chris Benmore, who works out of the U.S. Department of Energy's Argonne National Laboratory.
To turn cement into metal, the group of scientists from the United States, Japan, Finland, and Germany turned to a process known as electron trapping. Previously, electron trapping had only observed in ammonia mixtures, but through a careful melting process involving a levitator that keeps any of the liquid cement from touching any surfaces, scientists found a way to trap electronics in a cement mixture as well. What was once an insulator becomes a conductor, as the electrons that get trapped in the glass-like structure of the new metal form a roadway for electricity.
"This phenomenon of trapping electrons and turning liquid cement into liquid metal was found recently, but not explained in detail until now," Benmore said.
The metallic glass produced by the process is not only less prone to erosion (thanks to its glass qualities) than normal metal, but less brittle than normal glass (thanks to its metal qualities). Up until now, only metals have been able to make the transformation to metallic glass.
"Now that we know the conditions needed to create trapped electrons in materials we can develop and test other materials to find out if we can make them conduct electricity in this way," Benmore explained.
The findings were published in the Proceedings of the National Academy of Sciences in the article "Network topology for the formation of solvated electrons in binary CaO-Al2O3 composition glasses."