Deposition of Superconducting Nb3Sn Coatings Using Multiple Magnetron Sputtering Techniques

This paper describes the elemental and phase composition, microstructure, and superconducting properties of Nb3Sn deposited by magnetron sputtering. The films were deposited on sapphire substrates using three different techniques: co-evaporation, layer-by-layer deposition of Nb and Sn, and sputtering of a stoichiometric Nb3Sn target. The influence of magnetron operation mode on the as-deposited film element composition is described. After high-temperature annealing at 700-900 degree celsius, the results indicate the formation of superconductive films. The highest critical temperature of 16.9 K was obtained for the film deposited at a stoichiometric Nb3Sn target and annealed at a temperature of 800 degree celsius for 12 h. These results could be used for superconducting radio-frequency applications.