Stability Mechanisms of High Current Transport in Iron-Chalcogenide Superconducting Films

The improvement in the fabrication techniques of
iron-based superconductors have made these materials real
competitors of high temperature superconductors and MgB2. In
particular, iron-chalcogenides have proved to be the most
promising for the realization of high current carrying tapes. But
their use on a large scale cannot be achieved without the
understanding of the current stability mechanisms in these
compounds. Indeed, we have recently observed the presence of
flux flow instabilities features in Fe(Se,Te) thin films grown on
CaF2. Here we present the results of current-voltage characterizations
at different temperatures and applied magnetic fields on
Fe(Se,Te) microbridges grown on CaF2. These results will be
analyzed from the point of view of the most validated models
with the aim to identify the nature of the flux flow instabilities
features (i.e., thermal or electronic), in order to give a further
advance to the high current carrying capability of ironchalcogenide
superconductor