Ultra-High Performance, High-Temperature Superconducting Wires via Cost-effective, Scalable, Co-evaporation Process

Long-length, high-temperature superconducting (HTS) wires capable of carrying high critical current, I-c, are required for a wide range of applications. Here, we report extremely high performance HTS wires based on 5 mu m thick SmBa2Cu3O7-delta (SmBCO) single layer films on textured metallic templates. SmBCO layer wires over 20 meters long were deposited by a cost-effective, scalable co-evaporation process using a batch-type drum in a dual chamber. All deposition parameters influencing the composition, phase, and texture of the films were optimized via a unique combinatorial method that is broadly applicable for co-evaporation of other promising complex materials containing several cations. Thick SmBCO layers deposited under optimized conditions exhibit excellent cube-on-cube epitaxy. Such excellent structural epitaxy over the entire thickness results in exceptionally high I-c performance, with average I-c over 1,000 A/cm-width for the entire 22 meter long wire and maximum I-c over 1,500 A/cm-width for a short 12 cm long tape. The I-c values reported in this work are the highest values ever reported from any lengths of cuprate-based HTS wire or conductor.