  The improvement in the fabrication techniques of iron-based superconductors
have made these materials real competitors of high temperature superconductors
and MgB$_2$. 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
CaF$_2$. Here we present the results of current-voltage characterizations at
different temperatures and applied magnetic fields on Fe(Se,Te) microbridges
grown on CaF$_2$. 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 iron-chalcogenide
superconductors.
