Scientists at Argonne National Laboratory (US Department of Energy), together with a team of scientists from Japan, Finland and Germany, have discovered a way of turning liquid cement into liquid metal.
The team of scientists studied mayenite, a component of alumina cement made of calcium and aluminum oxides. They melted it at temperatures of 2000 °C using an aerodynamic levitator with carbon dioxide laser beam heating. The material was processed in different atmospheres to control the way that oxygen bonds in the resulting glass. The levitator keeps the hot liquid from touching any container surfaces and forming crystals. This let the liquid cool into glassy state that can trap electrons in the way needed for electronic conduction. As a semi-conductor, this opens cement up for use in the profitable consumer electronics marketplace for thin films, protective coatings, and computer chips.
“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 Chris Benmore, who led the research together with Shinji Kohara from Japan Synchrotron Radiation Research Institute/SPring-8.
This metallic-glass material has positive attributes, including better resistance to corrosion than traditional metal, less brittleness than traditional glass, conductivity, low energy loss in magnetic fields, and fluidity for ease of processing and moulding. Previously, only metals have been able to transition to a metallic-glass form. Cement does this by a process called electron trapping, a phenomena only previously seen in ammonia solutions. Understanding how cement joined this exclusive club opens the possibility of turning other solid normally insulating materials into room-temperature semiconductors.
The results were reported this week in the Proceeding of the National Academy of Sciences in the article “Network topology for the formation of solvated electrons in binary CaO–Al2O3 composition glasses”.
Further details about the project can be found on the Argonne National Laboratory website.
Adapted from press release by Katherine Guenioui.
Read the article online at: https://www.worldcement.com/the-americas/29052013/scientists_turn_liquid_cement_to_liquid_metal_997/