Influence of Isostatic Pressure on the Superconducting Performance of Nb₃Al Prepared by Low‐Temperature Sintering

Abstract

The influence of isostatic sintering pressure on the superconducting performance of Nb3Al prepared by powder metallurgy is investigated. It is found that its superconducting transition temperature (Tc) and critical current density ( Jc) are both improved with the increase in sintering pressure. Specifically, the Tc of the 180 MPa sintered sample reaches nearly 16.2 K, and its Jc is up to 1.1 × 104 A cm−2 (4.2K, 5T), an order of magnitude higher than that of the ambient sintered sample. The Nb/Al in the Nb3Al superconducting phase closer to the stoichiometric ratio of 3:1 in the pressure sintered samples is responsible for the increase in Tc; meanwhile, the reduced sintering micropores, refined grains, and more dislocations in the pressure sintered samples all contribute to the enhancement of their Jc.

Additional Flux Pinning in Sn‐Doped Nb3Al Superconductor

“…At present, the J c performance of Nb 3 Al has not yet reached the ideal value, for which researchers have made many attempts. [ 5–10 ] Doping has been proved to be one of the most effective ways to improve superconducting properties. [ 11–17 ] Doping of various metal elements, such as Ge, Ag, Ti, Si, and Ga, [ 11,12,16,18 ] into the Nb 3 Al superconductor has been tried.…”