Mechanism of enhancement of electromagnetic properties of MgB2 by nano-SiC doping

TL;DR

This study investigates how nano-SiC doping improves the electromagnetic properties of MgB2 superconductors by promoting C substitution and defect formation, leading to enhanced critical fields and current densities.

Contribution

It introduces a dual reaction model explaining SiC doping effects and predicts optimal dopants for MgB2 performance enhancement.

Findings

Hirr reached 10 T at 20 K in SiC-doped MgB2

C substitution increases Hc2 and Jc

Defects and nanoinclusions improve superconducting properties

Abstract

A comparative study of pure, SiC, and C doped MgB2 wires has revealed that the SiC doping allowed C substitution and MgB2 formation to take place simultaneously at low temperatures. C substitution enhances Hc2, while the defects, small grain size and nanoinclusions induced by C incorporation and low temperature processing are responsible for the improvement in Jc. The irreversibility field (Hirr) for the SiC doped sample reached the benchmarking value of 10 T at 20 K, exceeding that of NbTi at 4.2 K. This dual reaction model also enables us to predict desirable dopants for enhancing the performance properties of MgB2.