Effect of nano-C doping on the in-situ processed MgB2 tapes

TL;DR

This study investigates how nano-carbon doping affects the microstructure and superconducting performance of MgB2 tapes, showing improved critical current density due to finer grains and C substitution effects.

Contribution

It provides new insights into the effects of nano-C doping on microstructure and superconducting properties of MgB2 tapes prepared via in-situ method.

Findings

Nano-C doping results in smaller MgB2 grains.

Critical current density is enhanced in doped samples.

Lattice parameters decrease with increased doping.

Abstract

The effect of nano-C doping on the microstructure and superconducting properties of Fe-sheathed MgB2 tapes prepared through the in-situ powder-in-tube method was studied. Heat treatment was performed at a low temperature of 650C for 1 h. Scanning electron microscopy investigation revealed that the smaller grain size of MgB2 in the samples with the C-doping. Further, the a-axis lattice parameter and transition temperature decreased monotonically with increasing doping level, which is due to the C substitution for B. High critical current density Jc values in magnetic fields were achieved in the doped samples because of the very fine-grained microstructure of the superconducting phase obtained with C doping.