Sometimes a little damage can do a lot of good—at least in the case of iron-based high-temperature superconductors. Bombarding these materials with high-energy heavy ions introduces nanometer-scale damage tracks that can enhance the materials' ability to carry high current with no energy loss—and without lowering the critical operating temperature. Such high-current, high-temperature superconductors could one day find application in zero-energy-loss power transmission lines or energy-generating turbines. But before that can happen, scientists would like to understand quantitatively and in detail how the damage helps—and use that knowledge to strategically engineer superconductors with the best characteristics for a given application.
In a paper published May 22, 2015, in Science Advances, researchers from the U.S. Department of Energy's (DOE) Brookhaven and Argonne national laboratories describe atomic-level "flyovers" of the pockmarked landscape of an iron-based superconductor after bombardment with heavy ion radiation. The surface-scanning images show how certain types of damage can pin potentially disruptive magnetic vortices in place, preventing them from interfering with superconductivity.