Speaker
Description
To address the low superconducting transition temperature (Tc) of Cu-based Nb₃Sn films caused by Cu/Sn interdiffusion and thermal mismatch, Ta or Cr barrier layers (0.5/1 μm) together with Nb, Cu, and Sn were deposited on Cu substrates by magnetron sputtering using the bronze method, followed by three-step annealing. All films achieved Tc>17 K (max 17.42 K). The 0.5 μm Cr layer gave the narrowest transition width and higher Tc than the same?thickness Ta layer. XRD revealed that Cr promotes (210) preferred orientation, possibly due to interfacial Cr₂Nb formation. Cross?section EDS confirmed that Cr more effectively suppresses Sn back?diffusion to Cu. Overall, the 0.5 μm Cr barrier exhibits comprehensive advantages in superconductivity, diffusion inhibition, and texture control, offering a promising route for high?performance Cu?based Nb₃Sn superconducting cavities.