title: Interface control by homoepitaxial growth in pulsed laser deposited iron chalcogenide thin films.
abstract: Thin film growth of iron chalcogenides by pulsed laser deposition (PLD) is still a delicate issue in terms of simultaneous control of stoichiometry, texture, substrate/film interface properties, and superconducting properties. The high volatility of the constituents sharply limits optimal deposition temperatures to a narrow window and mainly challenges reproducibility for vacuum based methods. In this work we demonstrate the beneficial introduction of a semiconducting FeSe(1-x)Te(x) seed layer for subsequent homoepitaxial growth of superconducting FeSe(1-x)Te(x) thin film on MgO substrates. MgO is one of the most favorable substrates used in superconducting thin film applications, but the controlled growth of iron chalcogenide thin films on MgO has not yet been optimized and is the least understood. The large mismatch between the lattice constants of MgO and FeSe(1-x)Te(x) of about 11% results in thin films with a mixed texture, that prevents further accurate investigations of a correlation between structural and electrical properties of FeSe(1-x)Te(x). Here we present an effective way to significantly improve epitaxial growth of superconducting FeSe(1-x)Te(x) thin films with reproducible high critical temperatures (≥17 K) at reduced deposition temperatures (200 °C-320 °C) on MgO using PLD. This offers a broad scope of various applications.
authors.affiliation: Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, D-01314 Dresden, Germany.|Dresden University of Technology, Department of Physics, D-01062 Dresden, Germany.|IFW Dresden, P.O. Box 270116, 01171 Dresden, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Molatta
authors.affiliation: IFW Dresden, P.O. Box 270116, 01171 Dresden, Germany.|Physikalisches Institut, Universitat Tubingen, Auf der Morgenstelle 14, D-72076 Tubingen, Germany.
authors.forename: Silvia
authors.initials: S
authors.lastname: Haindl
authors.affiliation: Dresden University of Technology, Department of Physics, D-01062 Dresden, Germany.|IFW Dresden, P.O. Box 270116, 01171 Dresden, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Trommler
authors.affiliation: Dresden University of Technology, Department of Physics, D-01062 Dresden, Germany.|IFW Dresden, P.O. Box 270116, 01171 Dresden, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schulze
authors.affiliation: Dresden University of Technology, Department of Physics, D-01062 Dresden, Germany.|IFW Dresden, P.O. Box 270116, 01171 Dresden, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Wurmehl
authors.affiliation: IFW Dresden, P.O. Box 270116, 01171 Dresden, Germany.
authors.forename: Ruben
authors.initials: R
authors.lastname: Hühne