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.
Funding
Current limiting mechanisms in magnesium diboride superconductors
Dou, S. X., Shcherbakova, O. V., Yeoh, W., Kim, J., Soltanian, S., Wang, X., Senatore, C., Flukiger, R., Dhalle, M., Husnjak, O. & Babic, E. (2007). Mechanism of Enhancement in Electromagnetic Properties of MgB2 by Nano SiC Doping. Physical Review Letters, 98 097002-1-097002-4.