The vortex state of FeSe_{1 −<i>x</i>}Te_<i>x</i>superconducting thin films

Abstract

We report the vortex dynamics of tellurium substituted FeSe 1-x Te x superconducting thin films. The electric field versus current density (E-J ) curve for films with low Te substitution is still governed by the thermally activated flux flow model at temperatures as low as 0.5T offset C .I n contrast, we clearly observed a vortex liquid-glass transition in films with high Te substitution. The E-J curves of these samples fit nicely to the scaling relations based on the 3D vortex glass theory. Our results reveal an enhancement of the vortex pinning as more Te content is introduced, which probably originates from the excess Fe at the interstitial site.