Influence of low temperature-low oxygen pressure postannealing on critical current density of Bi(Pb)2223/Ag superconductors
文献类型：期刊论文
| 作者 | Deng, H ; Hua, PW ; Wang, WQ ; Dong, C ; Chen, H ; Wu, F ; Wang, XH ; Zhou, YR ; Yuan, GS |
| 刊名 | PHYSICA C
 |
| 出版日期 | 2000 |
| 卷号 | 339期号:3页码:181 |
| 关键词 | IN-TUBE TAPES CU-O SYSTEM BI-2223/AG TAPES (BI MECHANICAL DEFORMATION POWDER CALCINATION AEROSOL PRECURSOR PHASE-DIAGRAM COOLING RATE MICROSTRUCTURE PB)(2)SR2CA2CU3OX TAPES |
| ISSN号 | 0921-4534 |
| 通讯作者 | Deng, H: Gen Res Inst NonFerrous Met, Ctr Superconduct Res, 2 Xinjiekouwai Dajie, Beijing 100088, Peoples R China. |
| 中文摘要 | A Bi(Pb)2223/Ag multifilamentary tape was manufactured using the traditional PIT method. A series of the short samples cut from the tape were used to investigate the effect of low temperature-low oxygen pressure post-annealing on the critical current density of the samples. Two series of the air-sintered superconducting samples with the different intermediate pressing times and total sintering time were in situ post-annealed, respectively, under the reduced atmosphere taking the post-annealing temperature, time and oxygen partial pressure as variations. The results indicate that there are different effects of the post-annealing on the critical current density for the samples in the two series. Postannealing at the temperatures from 760 degrees C to 810 degrees C for a short time can improve the J(c) values up to 1.5-2.5 times for the samples in series 1, and the maximum value can be achieved at 780 degrees C, which makes the J(c)(A)/J(c)(B)-T (A: after the postannealing; B: before the post-annealing) curve present a single-peak form, whereas the J(c) values can be obviously improved up to 1.3-2.0 times at 820 degrees C and slightly improved at 780 degrees C for the samples in series 2, which makes the J(c)(A)/J(c)(B)-T curve present a double-peak form. XRD, SEM and ac susceptibility measurements indicate that the two different effects of the post-annealing, which closely depends on the sintering time of the samples before post-annealing, should be attributed to the two different phase transformations relating to the formation of(Bi,Pb)2212 and Bi2223, respectively, during the post-annealing. Formation of (Bi,Pb)2212 from Pb-poor Bi2212 and (Pb,Bi)(4-alpha)(Sr,Ca)(5-beta)CuOx (Pb451) at 780 degrees C for the samples with a shorter sintering time has an effect of improving the transition temperature of 2212 from 68-74 to 76-80 K and, therefore, overcomes the obstruction of the phase on the critical current at liquid nitrogen temperature and obviously improves the critical current density of the samples. The improvement of the J(c) values for the samples with a longer sintering time after being treated at 820 degrees C can be attributed to the formation of Bi2223 from Bi2212, Pb451 and (Sr,Ca)(14)Cu24Ox It seems that the effectiveness of post-annealing strongly depends on the sintering time of the samples before post-annealing: the formation of BiPb2212 at 780 degrees C needs a shorter time (relatively larger amount of Bi2212) in advance, whereas the formation of Bi2223 at 820 degrees C needs a longer time (decreased amount of Bi2212 and increased amount of (Sr,Ca)(14)Cu24Ox). Among the two phase transformations, the formation of Pb-enhanced Bi2212 at 780 degrees C seems to be of utmost importance and has a universal meaning for the manufacture of the Bi2223 tapes, which solves the intrinsic problem of the partial decomposition of Bi2223 during the furnace cooling and may present a new idea of improving the J(c) values through adjusting the transition temperature of the superconducting secondary phases besides the exhausted effort of making the Bi2223 single phase. The J(c) values after post-annealed at 780 degrees C for a short time for the samples with a shorter sintering time before the treatment can be comparable with that of the longer time sintered samples and the samples after post-annealed at 820 degrees C, which also reflects the importance of the transformation of Bi2212 into BiPb2212 on the critical current density of the tapes and makes the mechanism deserve to be further investigated. (C) 2000 Elsevier Science B.V. All rights reserved. |
| 收录类别 | SCI |
| 语种 | 英语 |
| 公开日期 | 2013-09-17 |
| 源URL | [http://ir.iphy.ac.cn/handle/311004/39841]  |
| 专题 | 物理研究所_物理所公开发表论文_物理所公开发表论文_期刊论文 |
| 推荐引用方式 GB/T 7714 | Deng, H,Hua, PW,Wang, WQ,et al. Influence of low temperature-low oxygen pressure postannealing on critical current density of Bi(Pb)2223/Ag superconductors[J]. PHYSICA C,2000,339(3):181. |
| APA | Deng, H.,Hua, PW.,Wang, WQ.,Dong, C.,Chen, H.,...&Yuan, GS.(2000).Influence of low temperature-low oxygen pressure postannealing on critical current density of Bi(Pb)2223/Ag superconductors.PHYSICA C,339(3),181. |
| MLA | Deng, H,et al."Influence of low temperature-low oxygen pressure postannealing on critical current density of Bi(Pb)2223/Ag superconductors".PHYSICA C 339.3(2000):181. |
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来源：物理研究所
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