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

The improvement in the fabrication techniques of iron-based superconductors has 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. However, 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 advance further to the high current-carrying capability of iron-chalcogenide superconductors.