Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9841783 | Physica C: Superconductivity and its Applications | 2005 | 5 Pages |
Abstract
We prepared filamentary 0.1Â at% Zr-doped (Nd0.33Eu0.38Gd0.28)Ba2Cu3Ox superconductors by solution spinning and partial melting in flowing 0.1% O2Â +Â Ar gas. The transport critical-current density (Jc) was measured at 77Â K in applied magnetic fields up to 14Â T by rotating the sample along a direction perpendicular to the filament length. Anisotropic behavior of the field dependence of Jc was detected by applying a field of more than 4Â T. The Jc values for the Zr-doped sample were higher than those for the undoped sample on the application of fields of up to 11Â T. The Jc values measured at the optimized angle for the doped sample were more than 105Â A/cm2 at 77Â K by applying fields of up to 6Â T. Transmission electron microscopy (TEM) of the sample was performed using an ultra high-voltage TEM to clarify the pinning centers. Intergrowth of 124 phase and stacking faults in the oriented 123 matrix were observed both for the doped and undoped samples. Zr doping resulted in the fluctuation of the structure with a short disorder range of 10-30Â nm. A modulated structure and fine twin planes crossing each other were partly observed for the doped sample. The presence of such small-scale disorder could improve flux pinning in the middle field region.
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Authors
T. Goto, E. Sato, K. Watanabe, G. Nishijima, Y. Matsui, T. Nagai, C. Tsuruta,