A study on the effect of deposition rate on superconducting properties in SmBCO superconducting wire production process

The effect of deposition rate on the superconducting properties in the manufacturing process of SmBCO superconducting thin films was investigated. The superconducting layer was deposited using the EDDC (Evaporation using Drum in Dual Chambers) deposition process. An apparatus for continuously changing the deposition rate was constructed with a shield having a triangular open area in one chamber. Sm1+xBa2Cu3+yO7 (SmBCO) superconducting thin film samples were fabricated by continuously increasing the deposition rate of the SmBCO superconducting layer in the longitudinal direction from 0 to 28 nm/min at the tape length of 12 cm in an atmosphere with a substrate temperature of 800 degrees C. The magnetic field dependence of the critical current was measured using the PPMS in the direction of the magnetic field parallel to the c axis of the superconducting thin film to found out the optimal deposition rate under magnetic field. The TEM analysis results confirmed the flux pinning centers of rod and particle shapes, and the flux pinning density was the highest in the sample with a deposition rate of 21 nm/min. These flux pinning centers formed by the combination of rod and particle shapes improved the critical current characteristics under the magnetic field of SmBCO superconducting wire.