Superconductivity in epitaxial thin films ofFe1.08Te:Ox

Superconducting thin films of ${\text{Fe}}_{1.08}\text{Te}:{\text{O}}_{x}$ have been epitaxially grown on ${\text{SrTiO}}_{3}$ substrates by pulsed-laser deposition in controlled oxygen atmosphere. Although the bulk ${\text{Fe}}_{1.08}\text{Te}$ is not superconducting, thin films with oxygen are superconducting with an onset and a zero resistance transition temperature around 12 and 8 K, respectively. Oxygen was found to be crucial to the superconducting properties of these films, suggesting that the oxygen incorporation can induce superconductivity in FeTe thin films. A metal-insulator transition is found at about 60 K, lower than that of bulk $(\ensuremath{\sim}70\text{ }\text{K})$. From magnetoresistive measurements, we obtained the irreversibility line and the upper critical field.