High quality epitaxial FeSe_0.5Te_0.5thin films grown on SrTiO₃substrates by pulsed laser deposition

Abstract

Superconducting epitaxial FeSe0.5Te0.5 thin films were prepared on SrTiO3\n(001) substrates by pulsed laser deposition. The high purity of the phase, the\nquality of the growth and the epitaxy were studied with different experimental\ntechniques: X-rays diffraction, reflection high energy electron diffraction,\nscanning tunnelling microscopy and atomic force microscopy. The substrate\ntemperature during the deposition was found to be the main parameter governing\nsample morphology and superconducting critical temperature. Films obtained in\nthe optimal conditions show an epitaxial growth with c axis perpendicular to\nthe film surface and the a and b axis parallel to the substrates one, without\nthe evidence of any other orientation. Moreover, such films show a metallic\nbehavior over the whole measured temperature range and critical temperature\nabove 17K, which is higher than the target one.\n