Synthesis of Nb and Alternative Superconducting Film to Nb for SRF Cavity as Single Layer

The production of superconducting coatings for radio frequency (RF) cavities has been developed over several decades. It is widely accepted that for any further improvement in cavity RF performance, innovation is needed and one may have to turn to other forms of Nb and other superconducting materials. The potential benefits of using materials other than Nb would be a higher Tc and a potentially higher critical field Hc. This could lead to potentially significant cryogenic cost reductions if the cavity operation temperature is 4.2 K or higher. We report on optimising deposition parameters and the effect of substrate treatment prior to deposition, on successful synthesis of Nb and A15 superconducting thin film. The materials characterization is determined using scanning electron microscopy SEM, energy dispersive spectroscopy EDS, glancing X-ray diffraction GXRD, atomic force microscopy AFM and Rutherford backscattering RBS. The DC superconducting properties have been tested using Vibrating Sample Magnetometer VSM and Magnetic Field Penetration MPF. This work involves a team of 8 research groups in 7 different countries and is part of the H2020 ARIES collaboration.