Vortex Pinning in Nanostructured Novel Superconductors

• Published in: Journal of superconductivity and novel magnetism 2017-03, Vol.30 (3), p.743-747
• Main Authors: Babić, E., Galić, S., Jerčinović, M., Kušević, I., Novosel, N., Pajić, D., Zadro, K.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Magnetic Materials; Magnetism; Original Paper; Physics; Physics and Astronomy; Strongly Correlated Systems; Superconductivity
• ISSN: 1557-1939; 1557-1947
• DOI: 10.1007/s10948-016-3649-1

The influence of magnetic nanoadditives (MN) on electromagnetic properties of MgB 2 wires is compared with the effects of nonmagnetic nanoadditives (NN) in bulk MgB 2 and with irradiation effects in HT c tapes. Both coated (carbon, silica, or dextrin shell) and uncoated MN were used in order to assess the effects of co-doping and interparticle interaction. Transport and magnetic measurements were used in order to determine connectivity, characteristic fields ( B i r r , B c 2 ), and J c of all wires. Light doping (≤3 wt%) enhances J c and/or B i r r for all types of MN, and indicates contribution of magnetic pinning. The enhancement of J c by the best MN is comparable to that for best NN. In both MN and NN doped MgB 2 , matching effects in vortex pinning appear causing a maximum enhancement of B i r r at higher temperatures, but sizable enhancement persists to the lowest temperatures. Matching effects also appear in irradiated HT c tapes, but with enhancement of B i r r limited to vicinity of matching field only. The advantage of enhanced B i r r at all temperatures in doped MgB 2 wires is practically annulled by poor connectivity.