A research team including EFree Director Ho-Kwang Mao (Carnegie), observed that crystalline long-range topological order can form in metallic glass made from Ce and Al. Their research reveals the possibility of creating a metallic glass that is organized on a larger scale. The team determined that the atomic structures of Ce and Al prevent the glass from assuming the highly ordered state at normal pressures. However, under intense pressure at 25 GPa, an electron in Ce shifts, allowing a face-centered cubic single crystal structure to be created. When the glass was brought back to ambient pressure, the new structural order was preserved.
Metallic glasses are a hot research topic because they are less brittle than ordinary glasses and more resilient than conventional metals. These results are exciting because they demonstrate that pressurized Ce-Al glass could be a favorable system for discovering the long-sought-after perfect glass. This situation could also exist in other metallic glasses [Q. Zeng, et al., Science 322,1404-1406 (2011)]
Figure Caption: An illustration of the process through which the atoms in Ce-Al glass become ordered and develop a crystalline structure under high pressure within a diamond anvil cell.