Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5492367 | Physica C: Superconductivity and its Applications | 2017 | 4 Pages |
Abstract
The comparison of nano-crystalline MgB2 oxygen-containing thin film (140 nm) and highly dense bulk materials showed that the critical current density, Jc, depends on the distribution of Mg-B-O nano-scale inhomogeneities. It has been shown that MgB2 bulks with high Jc in low (â¼106 A/cm2 in 0-1 T at 10 K) and medium magnetic fields contain MgB0.6-0.8O0.8-0.9 nano-inclusions, where δTc or a combined δTc (dominant) / δl pinning mechanism prevails, while in bulk MgB2 with high Jc in high magnetic fields (Birr(18.5 K) = 15 T, Bc2(0 K) = 42.1 T) MgB1.2-2.7O1.8-2.5 nano-layers are present and δl pinning prevails. The structure of oxygen-containing films with high Jc in low and high magnetic fields (Jc (0 Т) = 1.8 Ã 107 Ð/Ñm2 and Jc (5 Т) = 2 Ã 106 Ð/Ñm2 at 10 Ð) contains very fine oxygen-enriched Mg-B-O inhomogeneities and δl pinning is realized. The results of DOS calculations in MgB2-xOx cells for x = 0, 0.125, 0.25, 0.5, 1 demonstrate that all compounds are conductors with metal-like behaviour. In the case of ordered oxygen substitution for boron the binding energy, Eb, does not increase sufficiently as compared with that for MgB2, while when oxygen atoms form zigzag chains the calculated Eb is even lower (Eb = â1.15712 Ry).
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Tatiana Prikhna, Andrey Shapovalov, Michael Eisterer, Vladimir Shaternik, Wilfried Goldacker, Harald W. Weber, Viktor Moshchil, Artem Kozyrev, Vladimir Sverdun, Viktor Boutko, Gennadiy Grechnev, Alexandr Gusev, Valeriy Kovylaev, Anton Shaternik,