Irreversibility line and flux flow noise in superconducting Nb-Ta

Author

Otabe, E.S. ; Matsushita, T. ; Matsuno, T. ; Yamafuji, K.

Author_Institution

Dept. of Comput. Sci. & Electron., Kyushu Inst. of Technol., Iizuka, Japan

Volume

27

Issue

2

fYear

1991

fDate

3/1/1991 12:00:00 AM

Firstpage

1033

Lastpage

1036

Abstract

It has been found that the critical current density, J _c, in high-T_c oxide superconductors is reduced to zero at high temperatures and/or high magnetic fields even in a superconducting region. The irreversibility line was investigated in weakly pinned superconducting Nb-Ta with low T_c and was compared with that in oxide superconductors. Large flux flow noise with a peak around 0.3 Hz was observed in Nb-Ta specimens. The noise power integrated in the frequency range of 0.1-1.0 Hz had a sharp peak, when it was plotted against the magnetic field. The mechanism of such a characteristic noise is examined

Keywords

critical current density (superconductivity); flux flow; niobium alloys; noise; tantalum alloys; type II superconductors; 0.1 to 1.0 Hz; characteristic noise; critical current density; flux flow noise; irreversibility line; noise power; oxide superconductors; sharp peak; weakly pinned superconducting Nb-Ta; Critical current density; Frequency; High temperature superconductors; Magnetic field measurement; Magnetic fields; Magnetic noise; Superconducting device noise; Superconductivity; Temperature dependence; Temperature distribution;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.133354

Filename

133354