INVESTIGADORES
SERQUIS Adriana Cristina
artículos
Título:
Microstructure and high critical current of powder in tube MgB2
Autor/es:
A. SERQUIS; L. CIVALE; D. L. HAMMON; J. Y. COULTER; X. Z. LIAO; Y. T. ZHU; D. E. PETERSON; F. M. MUELLER
Revista:
APPLIED PHYSICS LETTERS
Editorial:
American Institute of Physics
Referencias:
Año: 2003 vol. 82 p. 1754 - 1756
ISSN:
0003-6951
Resumen:
We report dc transport and magnetization measurements of the critical current density, Jc , andmicrostructural analyses of MgB2 wires fabricated by the powder-in-tube method (PIT) usingcommercial MgB2 powder with 5 at.% Mg powder added as an additional source of magnesium and stainless steel as a sheath material.We identify a weak-link behavior in the as-drawn wire associated with the presence of microcracks. By appropriate heat treatments, we can increase Jc by more than one order of magnitude due to a recrystallization process promoted by the excess Mg, which results in the elimination of most of our microcracks. In contrast, inappropriate annealing conditions result in a deterioration of connectivity due to an inhomogeneous loss of Mg. Grain size and porosity play only a secondary role in determining Jc in PIT MgB2.
