2024-03-28T08:38:43Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/192552020-05-26T12:19:09Zcom_10261_31com_10261_3col_10261_284
Temperature and magnetic field dependence of the n-values of MgB2 superconductors
Martínez, Elena
Martínez-López, M.
Millán, Ángel
Mikheenko, P.
Critical currents
Magnetization relaxation effects
Superconductor
Resistivity
4 pages, 5 figures, 1 table.-- Trabajo presentado al: "Applied Superconductivity Conference" celebrado en Seattle(USA) el 27/08/2006.-- et al.
We analyse the temperature and magnetic field dependence of the power-law n-values characterizing the electric field-current density (E-J) curves of MgB2 superconducting samples. This is done by means of magnetic relaxation measurements, using the normalized relaxation rate of irreversible magnetization Mirr, S = -dlnMirr/dlnt, which directly relates to the E-J curve E infin Jn with the n-exponent approximately equal to 1 + 1/S. The study has been done at temperatures and fields ranging from (T = 5 K, B = 1 T) and up to (T, B) near the irreversibility line. Different samples such as undoped and SiC-doped bulk samples and wires have been analysed. We have observed a strong decrease in the n-values when increasing temperature and magnetic field with some differences among the analysed samples. We found correlation between critical current density (Jc) and n-values. The Jc(T, B) and n(T, B) dependences show striking similarities and the high n-values (n > 30) are always related to the high critical current densities (Jc > 108 A/m2).
2009-12-02T10:43:46Z
2009-12-02T10:43:46Z
2007-06
artículo
IEEE Transactions on Applied Superconductivity 17(2): 2738-2741 (2007)
1051-8223
http://hdl.handle.net/10261/19255
10.1109/TASC.2007.899555
eng
http://dx.doi.org/10.1109/TASC.2007.899555
closedAccess
Institute of Electrical and Electronics Engineers