NBN SUPERCONDUCTING THIN-FILMS GROWN BY PULSED-LASER ABLATION

NbN superconducting thin films have been grown by using pulsed laser a blation in a N-2 pure atmosphere. The X-ray spectra indicate that high ly oriented superconducting NbN films having a FWHM of the 002 reflect ion narrower than 0.5 degrees, has been obtained. Critical zero resist ance temperature T-c higher than 16.3 K and resistivity ratio approxim ate to 1.3 were measured as well as critical field of 12 T at LHe temp erature on the high quality films. Transport critical current density J(c), measured on a patterned film with a 50 mu V cm criteria, gave an extrapolated value of J(c0) higher than 1 x 10(7) A/cm(2) computed by using a Kim Andersen model. Preliminary photoemission spectroscopy me asurements in the presence of N-2 background gas indicate some reactiv ity in the plume region.