Superconducting properties of FeSe$_{0.5}$Te$_{0.5}$ and FeTe:O$_x$ thin films

High quality superconducting thin films of FeSe$_{0.5}$Te$_{0.5} $ and FeTe:O$_x$ have been grown by pulsed laser deposition on various substrates including coated conductor. Thin films of FeSe$_{0.5}$Te$_{0.5}$ have a higher superonducting transition temperature Tc (onset start around 20K and zero resistance about 16~17K) than that of bulk. High resolution transmission electron microscopy has identified a microstructure only in thin films, which may be associated with the higher Tc. Magneto-transport measurement has been carried out to check the angular dependence of upper critical field Hc2 and the critical current density of the films with the direction of magnetic field. Both have shown a weak anisotropy. These films have a special high dHc2/dT at Tc, especially for FeTe:O$_x$ film.