2003/11/18 by I. Kusevic, I. Kušević, E. Babic +7
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Physics of Superconductivity and Magnetism #Superconductivity in MgB2 and Alloys #cond-mat.mtrl-sci #cond-mat.supr-con
paper · pdf · doi:10.1016/j.ssc.2004.09.035
4 pages, 4 figures
arxiv created 2003/11/18 · openalex publication_date 2004/09/30 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The magnetoresistivity and critical current density of well characterized Si-nanoparticle doped and undoped Cu-sheathed MgB2 tapes have been measured at temperatures T≥ 28 K in magnetic fields B≤ 0.9 T. The irreversibility line Birr(T) for doped tape shows a stepwise variation with a kink around 0.3 T. Such Birr(T) variation is typical for high-temperature superconductors with columnar defects (a kink occurs near the matching field % Bϕ) and is very different from a smooth Birr(T) variation in undoped MgB2 samples. The microstructure studies of nanoparticle doped MgB2 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.