Naslov
Enhancement of the critical current density in MgB2 wires doped with Ni nanoparticles

Autori
Novosel, Nikolina ; Galić, Stipe ; Pajić, Damir ; Skoko, Željko ; Lončarek, Ivana ; Mustapić, Mislav ; Zadro, Krešo ; Babić, Emil

Izvornik
Superconductor science and technology (0953-2048) 25 (2012); 095018, 9

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
MgB2/Fe wires ; magnetic nanoparticle doping ; transport properties ; magnetic pinning

Sažetak
Iron-sheathed MgB2 wires doped with 0, 1.3 and 2.52 wt% carbon protected nickel superparamagnetic nanoparticles (the average diameter of the particles is 20 nm) and sintered at 650°C were prepared. X-ray diffraction patterns and magnetization measurements showed that neither substitution of C for B nor substitution of Ni for Mg occurred during the synthesis process. Scanning electron microscopy imaging of the doped sample revealed a homogeneous distribution of nickel particles within the MgB2 matrix. Transport (magnetoresistivity R(T, B) and critical current density Jc(B) in the temperature range 1.5-40 K) and magnetic measurements (magnetic hysteresis loops at temperatures below and above the superconducting transition temperature) were performed on Fe-sheathed wires and the superconducting cores of these wires. A small enhancement of the irreversibility field Birr(t=Tirr(B)/Tirr(0)) of the doped wires was observed in the low field range. Significant enhancement of Jc(B), especially at low temperature (5 K), was observed: at 5 K and 10 T, for both doped wires, Jc is 2.5 times larger than that for the undoped wire.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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