Pregled bibliografske jedinice broj: 272480
Enhanced flux pinning in nanostructured novel superconductors
Enhanced flux pinning in nanostructured novel superconductors // Fifth International Conference on Inorganic Materials - Delegate Manual
Ljubljana, Slovenija: Elsevier, 2006. str. 148-148 (poster, nije recenziran, sažetak, znanstveni)
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Naslov
Enhanced flux pinning in nanostructured novel superconductors
Autori
Kušević, Ivica ; Husnjak, Ozren ; Babić, Emil ; Soltanian Saeid ; Dou, Shi Xue
Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni
Izvornik
Fifth International Conference on Inorganic Materials - Delegate Manual
/ - : Elsevier, 2006, 148-148
Skup
Fifth International Conference on Inorganic Materials
Mjesto i datum
Ljubljana, Slovenija, 23.09.2006. - 26.09.2006
Vrsta sudjelovanja
Poster
Vrsta recenzije
Nije recenziran
Ključne riječi
MgB2; Nanostructured superconductors; New materials; Flux pinning
Sažetak
A systematic study of the parameters (irreversibility field Birr, critical current density, Jc) associated with flux pinning in nanoparticle doped (Si, SiC, average size 50 nm) powder-in-tube processed MgB2/Cu composite tapes has been carried out. Birr and Jc of undoped and doped (5 and 10 wt.%) tapes were measured in the temperature range 4-38 K and in magnetic fields up to 16 T. Birr(T) of doped tapes shows a change in slope around characteristic field B_fi which increases with nanoparticle content and also depends on their type. This indicates matching effect in flux pinning, probably associated with Mg2Si nanoprecipitates (~10 nm) formed during heat treatment. The flux pinning enhancement factor Birr(doped)/Birr(undoped), was the highest around the matching field B_fi (the field at which the areal density of precipitates matches that of flux lines) but remained high ~1.5 even for Birr>>B_fi (low temperatures). This feature contrasts sharply with matching field effects in high temperature superconductors containing columnar defects (where the enhancement is confined to fields <3B_fi), and is probably due to alloying effects (SiC) or/and wide distribution in nanoprecipitate sizes. The Birr values of doped tapes exceed those of optimised Nb-Ti wires (10 T, 4.2 K) already at 15 K. The variations of Jc with magnetic field B support the above findings, B has lesser influence on Jc in tapes with higher B_fi. The impact of these results on the future enhancement of flux pinning in MgB2 superconductor is briefly discussed.
Izvorni jezik
Engleski
Znanstvena područja
Fizika
