Improved superconducting properties of melt-textured Nd123 by additional heat treatment

被引:33
作者
Chikumoto, N [1 ]
Yoshioka, J [1 ]
Murakami, M [1 ]
机构
[1] ISTEC, Int Superconduct Technol Ctr, Superconduct Res Lab, Minato Ku, Tokyo 105, Japan
来源
PHYSICA C | 1997年 / 291卷 / 1-2期
关键词
Nd-Ba-Cu-O; melt process; heat-treatment; critical current density; critical temperature;
D O I
10.1016/S0921-4534(97)01705-X
中图分类号
O59 [应用物理学];
学科分类号
摘要
We have investigated the effect of additional heat-treatment on the superconducting transition and the flux pinning properties of Nd-Ba-Cu-O melt-textured in air. After the heat-treatment at high temperatures, > 900 degrees C, under low oxygen partial pressure, P(O-2) = 0.001 atm, the superconducting transition became sharper accompanied by an increase of J(c). However, the increase of J(c) was very small and the secondary peak effect commonly observed in Nd-Ba-Cu-O melt textured in low P(O-2) could not be observed. Transmission electron microscopic observations and energy dispersive X-ray analyses show that the spatial variation of the Nd/Ba ratio is reduced after high-temperature heat-treatment, which indicates that an improvement in T-c and J(c) is attributed to a suppression of Nd substitution on the Ba site. (C) 1997 Elsevier Science B.V.
引用
收藏
页码:79 / 84
页数:6
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