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Composition and microstructural evolution of nonsuperconducting phases in silver-clad (Bi,Pb)2Sr2Ca2Cu3Ox composite conductors

Published online by Cambridge University Press:  03 March 2011

J.S. Luo
Affiliation:
Argonne National Laboratory, Argonne, Illinois 60439-4837
N. Merchant
Affiliation:
Argonne National Laboratory, Argonne, Illinois 60439-4837
E.J. Escorcia-Aparicio
Affiliation:
Argonne National Laboratory, Argonne, Illinois 60439-4837
V.A. Maroni
Affiliation:
Argonne National Laboratory, Argonne, Illinois 60439-4837
B.S. Tani
Affiliation:
Argonne National Laboratory, Argonne, Illinois 60439-4837
W.L. Carter
Affiliation:
American Superconductor Corporation, Westborough, Massachusetts 01581
G.N. Riley Jr.
Affiliation:
American Superconductor Corporation, Westborough, Massachusetts 01581
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Abstract

The composition and microstructural evolution of nonsuperconducting phases during the course of formation of (Bi,Pb)2Sr2Ca2Cu3Ox (Bi-2223) in a silver sheath have been investigated by x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), and digital image analysis. Wire samples fabricated by the oxide-powder-in-tube technique were heat-treated under a variety of conditions (time, temperature, and oxygen pressure). Backscattered images taken on polished but unetched transverse cross sections were subjected to computerized image processing, which allowed determination of the stoichiometry and quantification of microstructural characteristics (such as area fraction, size distribution, position, and orientation) of each nonsuperconducting particle. The dominant nonsuperconducting phases observed by SEM/EDX were CuO, (Ca,Sr)2CuO3 (2/1), and (Ca, Sr)14Cu24O41 (14/24) in amounts that varied depending on the annealing temperature, time, and oxygen partial pressure. Time evolution studies performed at 825 °C in 0.075 atm O2 showed that the area fraction of 2/1 decreased with reaction time, while that for 14/24 increased. In all cases, a substantial amount (>10% area fraction) of nonsuperconducting phases was detected even after all the Bi2Sr2CaCu2Oy (Bi-2212) in the as-rolled composite conductor was fully converted to Bi-2223, as determined by XRD. High aspect ratio nonsuperconducting particles were initially randomly oriented in the composite conductor core but gradually aligned parallel to the silver/(Bi,Pb)-Sr-Ca-Cu-O interface after extended annealing. They tended to segregate and exhibited a much broader size distribution when processing was carried out at temperatures and oxygen partial pressures on the high end of the normal processing range, most likely as a result of the occurrence of partial melting in the system.

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Articles
Copyright
Copyright © Materials Research Society 1994

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References

REFERENCES

1Sato, K., Hikata, T., Mukai, H., Ueyama, M., Kato, T., Masuda, T., Nagata, M., Iwata, K., and Mitsui, T., IEEE Trans. Magn. 27, 1231 (1991).CrossRefGoogle Scholar
2Motowidlo, L. R., Gregory, E., Haldar, P., Rice, J. A., and Blaugher, R. D., Appl. Phys. Lett. 59, 736 (1991).CrossRefGoogle Scholar
3Malozemoff, A., Carter, W. L., Gannon, J., Joshi, C. H., Miles, P., Minot, M., Parker, D., Riley, G. N. Jr., Thompson, E., and Yurek, G., Cryogenics 32, 478 (1992).Google Scholar
4Yamada, Y., Obst, B., and Flukiger, R., Supercon. Sci. Technol. 4, 165 (1991).CrossRefGoogle Scholar
5Sandhage, K. H., Riley, G. N. Jr., and Carter, W. L., J. Met. 43, 21 (1991).Google Scholar
6Hellstrom, E. E., Mater. Res. Bull. XVII, 45 (1992).CrossRefGoogle Scholar
7Kato, T., Hikata, T., Ueyama, M., Sato, K., and Iwasa, Y., Mater. Res. Bull. XVII, 52 (1992).CrossRefGoogle Scholar
8Majewski, P., Hettich, B., Jaeger, H., and Schulze, K., Adv. Mater. 3, 67 (1991).CrossRefGoogle Scholar
9Wong-Ng, W., Chiang, C. K., Freiman, S. W., Cook, L. P., Hwang, N. M., and Hill, M. D., Ceram. Soc. Bull. 71, 1261 (1992).Google Scholar
10Oh, S. S. and Osamura, K., Supercon. Sci. Technol. 4, 239 (1991).CrossRefGoogle Scholar
11Zhu, W. and Nicholson, P. S., J. Mater. Res. 7, 38 (1992).Google Scholar
12Merchant, N., Luo, J. S., Maroni, V. A., Sinha, S. N., Riley, G. N. Jr., and Carter, W. L., Appl. Supercond. 2, 217 (1994).Google Scholar
13Luo, J. S., Faudot, F., JChevalier, -P., Portier, R., and Michel, D., J. Solid State Chem. 89, 94 (1990).CrossRefGoogle Scholar
14Chen, F. H., Koo, H. S., and Tseng, T. Y., Appl. Phys. Lett. 58, 637 (1991).CrossRefGoogle Scholar
15Sung, Y. S. and Hellstrom, E. E., Abstracts of the 1992 Fall Meeting of the MRS (Abstract No. H6.48), Boston, MA (1992).Google Scholar
16Luo, J. S., Merchant, N., Maroni, V. A., Gruen, D. M., Tani, B. S., Carter, W. L., Riley, G. N. Jr., and Sandhage, K. H., Appl. Supercon. 1, 101 (1993).Google Scholar
17Morgan, P. E., Housley, R. M., Porter, J. R., and Ratto, J. J., Physica C 176, 279 (1991).Google Scholar
18Dorris, S. E., Prorok, B. C., Lanagan, M. T., Sinha, S., and Poeppel, R. B., Physica C 212, 66 (1993).CrossRefGoogle Scholar
19Carter, W. L., Riley, G. N. Jr., Luo, J. S., Merchant, N., and Maroni, V. A., Appl. Supercon. 1, 1523 (1993).CrossRefGoogle Scholar
20Merchant, N., Luo, J. S., Maroni, V. A., Gruen, D. M., Tani, B. S., Sinha, S., Sandhage, K. H., and Craven, C. A., J. Mater. Res. 7, 2680 (1992).Google Scholar
21NIH Image, Version 1.49, Wayne Rasband, author, National Institutes of Health, Washington, DC.Google Scholar
22Huang, Y. T., Wang, W. N., Wu, S. F., Shei, C. Y., Huang, W. M., Lee, W. H., and Wu, P. T., J. Am. Ceram. Soc. 73, 3507 (1990).CrossRefGoogle Scholar
23Strobel, P., Toledano, J. C., Morin, D., Schneck, J., Vacquier, G., Monnereau, O., Primot, J., and Fournier, T., Physica C 201, 27 (1992).Google Scholar
24Endo, U., Koyama, S., and Kawai, T., Jpn. J. Appl. Phys. 27, L1476 (1988).CrossRefGoogle Scholar
25Luo, J. S., Merchant, N., Maroni, V. A., Gruen, D. M., Tani, B. S., Carter, W. L., Riley, G. N. Jr., and Sandhage, K. H., J. Appl. Phys. 72, 2385 (1992).CrossRefGoogle Scholar
26High, Y. E., Feng, Y., Sung, Y. S., Hellstrom, E. E., and Larbalestier, D. C., Physica C 220, 81 (1994).CrossRefGoogle Scholar
27Roth, R. S., Rawn, C. J., Ritter, J. J., and Burton, B. P., J. Am. Ceram. Soc. 72, 1545 (1989).Google Scholar
28Majewski, P., Hettich, B., Ruffer, N., and Aldinger, F., J. Elec. Mater. 22, 1259 (1993).CrossRefGoogle Scholar