Effect of carbon on the structure and superconducting properties of Nb3Sn coatings produced by electrocodeposition

The effect of carbon doping on the structure and superconducting properties of Nb3Sn coatings Produced by electrocodeposition of Nb and Sm from molten salts was investigated. The results demonstrate that the addition of fine-particle graphite powder to the melt has an insignificant effect on the microstructure. critical current, and superconducting transition temperature T-C of the coatings but reduces the superconducting transition width (DeltaT(C) less than or equal to 0.05). Doping of Nb3Sn with carbon from the gas phase (Ar + CCl4) ensures the formation of a fine-grained microstructure and increases the critical current of the material by a factor of 3-3.5 compared to coatings grown in pure argon atmosphere.