Effect of grain size and doping level of SiC on the superconductivity and critical current density in MgB/sub 2/ superconductor

Authors

Saeid Soltanian, University of WollongongFollow
Xiaolin Wang, University of WollongongFollow
J. Horvat, University of WollongongFollow
M. J. Qin, University of WollongongFollow
Hua-Kun Liu, University of WollongongFollow
P. R. Munroe, University of New South Wales
S. X. Dou, University of WollongongFollow

RIS ID

9647

Publication Details

This article was originally published as: Soltanian, S, Wang, X, Horvat, J et al, Effect of grain size and doping level of SiC on the superconductivity and critical current density in MgB/sub 2/ superconductor, IEEE Transactions on Applied Superconductivity, June 2003, 13(2)3, 3273-3276. Copyright IEEE 2003.

Abstract

SiC doped MgB/sub 2/ polycrystalline samples were fabricated by in-situ reaction using different grain sizes (20 nm, 100 nm, and 37 /spl mu/m) of SiC and different doping levels (0, 8, 10, 12, 15 wt%). Phases, microstructures, superconductivity, critical current density and flux pinning have been systematically investigated using XRD, SEM, TEM, and magnetic measurements. Results show that grain sizes of the starting precursors of SiC have a strong effect on the critical current density and its field dependence. The smaller the SiC grains are, the better the J/sub c/ field performance is. Significant enhancement of J/sub c/ and the irreversibility field H/sub irr/ were revealed for all the SiC doped MgB/sub 2/ with additions up to 15 wt%. A J/sub c/ as high as 20,000 A/cm/sup 2/ in 8 Tesla at 5 K was achieved for the sample doped with 10 wt% SiC with a grain size of 20 nm. Results indicate that the nano-inclusions and substitution inside MgB/sub 2/ are responsible for the enhancement of flux pinning.