Comparison of the Pinning Behavior of Nb3Al Superconductors Prepared by MAT and RHQT Methods

Although grain boundary pinning as the main source has been clarified in A15-structured superconductors, the pinning properties in high-performance Nb 3 Al are still poorly understood. In this paper, a comparative study of the pinning behavior of some typical Nb 3 Al samples prepared by MAT and RHQT methods, which have different superconducting properties in T c , J c , H irr , and F p , is investigated. It is observed that the scaling behavior of the pinning force of these samples is dominated by the planar pinning mechanism, characterized by h * ≈ 0.2; however, it is interesting to find that scaling exponents p and q appear to vary with sample’s performance: when F p,max > 1 GN/m 3 , the characteristics of the p - F p,max and q - F p,max curves are different from those at F p,max