Vortex flux pinning mechanism and enhancement of in-field Jc in succinic acid doped MgB2

• Published in: Solid state communications 2013-08, Vol.168, p.1-5
• Main Authors: Ghorbani, S.R., Darini, M., Wang, X.L., Hossain, M.S.A., Dou, S.X.
• Format: Article
• Language: English
• Subjects: A. Succinic acid doped MgB2; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Critical currents; D. Critical current density; D. Flux pinning mechanism; Exact sciences and technology; Physics; Properties of type I and type II superconductors; Superconductivity; Vortex lattices ,flux pinning, flux creep
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2013.06.010

The field dependence of the resistivity and the critical current density, Jc(B), of MgB2 doped with 10wt% wet and dry succinic acid have been investigated by magnetic measurements. The dry succinic acid significantly enhanced the upper critical field, the irreversibility field, and the Jc(B) compared to the wet succinic acid doped MgB2 and the pure MgB2. The field dependence of Jc(B) was analyzed within the collective pinning model. The observed temperature dependence of the crossover field, Bsb(T), from the single vortex to the small vortex bundle pinning regime shows that flux pinning arising from variation in the critical temperature, δTc, is the dominant mechanism for the wet sample over the whole studied temperature range, while there is a competition between δTc pinning and the pinning from variation in the mean free path, δl, for the dry sample. •The dry succinic acid doped MgB2 significantly enhanced the Jc, the Hc2, and the Hirr.•Different flux pinning mechanisms was found for the dry and the wet succinic acid doped MgB2.•δTc is the dominant mechanism for the wet sample while the δl pinning mechanism is dominant for the dry sample.