In the pantheon of unconventional superconductors, iron selenide is a rock star. But new experiments by U.S., Chinese and European physicists have found the material’s magnetic persona to be unexpectedly mundane.
Rice University physicist Pengcheng Dai, corresponding author of a study of the results published online this week in Nature Materials, offered this bottom-line assessment of iron selenide: “It’s a garden-variety iron-based superconductor. The fundamental physics of superconductivity are similar to what we find in all the other iron-based superconductors.”
That conclusion is based on data from neutron scattering experiments performed over the past year in the U.S., Germany and the United Kingdom. The experiments produced the first measurements of the dynamic magnetic properties of iron selenide crystals that had undergone a characteristic structural shift that occurs as the material is cooled but before it is cooled to the point of superconductivity.