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Nb3Sn, NbTiN and NbN are superconductors with a critical temperatures of 18.3, 12.6-17, 11.6-17.5 K, respectively, that are higher than that of Nb (9.3 K). Hence, at 4 K they have an RF resistance of an order of magni-tude lower than that of Nb, which leads to quality factors above those of Nb. In recent years, there has been an extensive effort converting Nb cavities into Nb3Sn by alloying the top inner layer of the cavity using Sn diffusion at a high temperature with some degree of success, however, the reproducibility remains a major hindering and limiting factor.
In this study, we report on PVD deposition of NbTiN inside 6 GHz cavity in an external magnetic coil configu-ration. The deposition is done at elevated temperature of about 650 C.
We report on the superconducting properties, film structure and its stoichiometry and surface chemical state. The films have been characterised with SEM, XRD, XPS, EDS and SQUID magnetometer.
