Measurement of critical current density Jc, normal state resistivity ρn, and upper critical field Hc2on pure and 10% SiC-doped MgB2bulks show systematic enhancement of Hc2by SiC addition and by lowering reaction temperature. Hc2(10 K) exceeds 33 T, while the extrapolated zero temperature value exceeds 40 T. The Rowell [Supercond. Sci. Technol. 16, R17 (2003)] analysis suggests that only 8%-17% of the MgB2cross section actually carries current. Higher reaction temperature enhances the connectivity but degrades Hc2and flux pinning, making the measured Jca complex balance between connectivity, Hc2, and flux pinning induced by grain boundaries and precipitates.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)