Fabrication of Fe–Te–S Superconducting Epitaxial Thin Films by Pulsed Laser Deposition

We report on the fabrication of Fe–Te–S epitaxial thin films on SrTiO 3 (100) and MgO(100) single crystal substrates by pulsed laser deposition. Crystal structure was checked by X-ray diffraction, composition by scanning electron microscopy and energy dispersive spectroscopy (SEM–EDS), and superconductivity by resistance measurements. All the films deposited in the temperature range 300–400 °C were grown epitaxially on both substrates with a 4-fold symmetry. A zero resistance condition was not reached, but even if the films present a stoichiometric excess of Fe there is a clear upturn at 6 K.