Multifilamentary, in-situ Route, Cu-stabilized MgB2 Strands

TL;DR

This study investigates the critical current densities of multifilamentary MgB2 strands with different barrier materials and additives, using simple heat treatments, revealing promising performance metrics at low temperatures and high magnetic fields.

Contribution

It presents a comprehensive analysis of in-situ route MgB2 strands with various barrier materials and additives, demonstrating their critical current densities under different conditions.

Findings

Critical current density of 1.75 x 10^5 A/cm^2 at 4.2 K and 5 T

Effective performance with simple heat treatments

Comparable performance across different barrier materials

Abstract

Transport critical current densities and n-values were measured at 4.2 K in fields up to 15 T on 7, 19, and 37-stack multifilamentary MgB2 strands made using an in-situ route. Some strands included SiC additions (particle size 30 nm), while in others Mg-rich compositions were used. Two basic multifilamentary variants were measured, the first had Nb filamentary barriers, the second had Fe filamentary barriers. All samples incorporated stabilizer in the form of Cu 101. Simple, one-step heat treatments were used, with temperatures ranging from 700-800C, and times from 10-30 minutes. Transport critical current densities of 1.75 x 105 A/cm2 were seen at 4.2 K and 5 T in 37 stack strands.