Naslov
Correlated vortex pinning in Si-nanoparticle doped MgB_2

Autori
Kušević, Ivica ; Babić, Emil ; Husnjak, Ozren ; Soltanian, Saeid ; Wang, X.L. ; Dou, Shi Xue

Izvornik
Solid State Communications (0038-1098) 132 (2004), 11; 761-765

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

Ključne riječi
vortex pinning; doping; MgB2

Sažetak
The magnetoresistivity and critical current density of well characterized Si-nanoparticle doped and undoped Cu-sheathed MgB$_{;2};$ tapes have been measured at temperatures $T\geq 28$ K in magnetic fields $B\leq 0.9$ T. The irreversibility line $B_{;irr}; (T)$ for doped tape shows a stepwise variation with a kink around 0.3 T. Such $B_{;irr}; (T)$ variation is typical for high-temperature superconductors with columnar defects (a kink occurs near the matching field $% B_{;\phi };$) and is very different from a smooth $B_{;irr}; (T)$ variation in undoped MgB$_{;2}; $ samples. The microstructure studies of nanoparticle doped MgB$_{;2}; $ samples show uniformly dispersed nanoprecipitates, which probably act as a correlated disorder. The observed difference between the field variations of the critical current density and pinning force density of the doped and undoped tape supports the above findings.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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