Enhancement of Critical Current Density of Nb₃Al Superconductors by B Doping

Abstract

Boron (B)‐doped Nb3Al superconductors were prepared by mechanical alloying (MA) and subsequent sintering process in this work. Then the critical current density (J c ) of Nb3Al with different amounts of B doping was studied. The results show that J c performance of Nb3Al is improved obviously after B doping. The best J c value obtained in this work is 2.2×104 A·cm‐2 (4.2 K, 5 T) for Nb3(Al0.9B0.1) sample. Furthermore, the mechanism of enhanced J c performance for Nb3(Al0.9B0.1) sample was comprehensively explored. We found that B doping can significantly enhance the grain connectivity of Nb3Al superconductor, and the active cross‐sectional area fraction (A F ) values increase from 0.11 for the undoped sample to 0.34 for Nb3(Al0.9B0.1) sample. Besides, the lattice distortion caused by the interstitially‐dissolved B may also serve as flux pinning centers, which strengthens the flux pinning force of Nb3(Al0.9B0.1).This article is protected by copyright. All rights reserved.