Superconducting Properties of CO₂ Laser Beam Irradiated Nb₃Al

Abstract

Laser irradiated Nb₃Al superconductors showed critical temperatures T_C above 16.0K and subsequent heat-treatment at 750°C enhanced the T_C to 18.6K. For laser irradiated and then heat-treated specimens, critical currents I_C were little decreased, even over 20T, as compared with specimens which were only heat-treated. A maximum critical current density J_C for reacted area of 4.8×10⁴A/cm² was obtained at 23T and 4.2K. The effects of temperature change and magnetic field direction on I_C were also discussed.