Unabridged phase diagram for single-phased FeSexTe1-x thin films

摘要

A complete phase diagram and its corresponding physical properties areessential prerequisites to understand the underlying mechanism of iron basedsuperconductivity. For the structurally simplest 11 (FeSeTe) system, earlierattempts using bulk samples have not been able to do so due to the fabricationdifficulties. Here, thin FeSexTe1-x films with the Se content covering the fullrange were fabricated by using pulsed laser deposition method. Crystalstructure analysis shows that all films retain the tetragonal structure in roomtemperature. Significantly, the highest superconducting transition temperature(TC = 20 K) occurs in the newly discovered domain, 0.6 - 0.8. The single-phasedsuperconducting dome for the full Se doping range is the first of its kind iniron chalcogenide superconductors. Our results present a new avenue to explorenovel physics as well as to optimize superconductors.