High field vortex phase diagram of Fe(Se,?Te) thin films

We report on the (H, T) vortex phase diagram up to 35?T of Fe(Se, Te) thin films deposited on CaF2 substrates as determined by resistivity, Nernst effect and critical current measurements. We found the presence of a large region where the vortex is firmly pinned, allowing the adoption of chalcogenides for low temperature but extremely high magnetic field applications. The fact that high critical current density values?larger than 1?MA?cm?2 in self-field and liquid helium?are reached together with a very weak dependence on the magnetic field and a complete isotropy, joined with the very high rigidity of the vortex lattice at very high field, makes the Fe(Se, Te) phase very promising for low temperature (?4.2?K) and high field (?25?T) applications.