Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-06T02:13:01.119Z Has data issue: false hasContentIssue false

Reaction pathways for the formation of the YBa2Cu3O7−x compound

Published online by Cambridge University Press:  31 January 2011

Eli Ruckenstein
Affiliation:
Department of Chemical Engineering, State University of New York–Buffalo, Buffalo, New York 14260
Sanjeev Narain
Affiliation:
Department of Chemical Engineering, State University of New York–Buffalo, Buffalo, New York 14260
Nae-Lih Wu
Affiliation:
Department of Chemical Engineering, State University of New York–Buffalo, Buffalo, New York 14260
Get access

Abstract

The kinetics of the reactions that lead to the formation of YBa2Cu3O7−x was investigated starting from various powder mixtures containing different reactants as sources of Ba, Cu, and Y (BaCO3, BaO, CuO, Y2O3. Y2Cu3O5. and BaCuO2). These powders were calcined at 940 °C for various time intervals. Quantitative x-ray analysis was used to determine the relative amounts of the compounds present in the calcined powders. When BaCO3 was used as the source of barium, long calcination times were required to obtain the single phased YBa2Cu3O7−x because of the slow decomposition of BaCO3. This leads to large particles and broad particle size distributions and hence to a lower density of the sintered superconducting pellets. Procedures to attain high density superconducting material are identified on the basis of the kinetic studies. Each of them isolates the slow reaction in a first step and prepares the superconducting material via a rapid reaction in a second step. The kinetic studies reveal the reaction mechanisms that were followed in different cases.

Type
Articles
Copyright
Copyright © Materials Research Society 1989

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Hepp, A. F., Gaier, J. R., Philipp, W. H., Warner, J. D., and Garlick, R. J., Mater. Res. Bull. Symp. 99, 615 (1988).CrossRefGoogle Scholar
2Kwestrov, W., Vanhal, H. A. M., and Langereis, C., Mater. Res. Bull. 9, 16311638 (1974).CrossRefGoogle Scholar
3Narain, S., Wu, N. L., and Ruckenstein, E., Mater. Lett. 6, 321 (1988).Google Scholar
4Ruckenstein, E. and Wu, N. L., Mater. Lett. 7, 165 (1988).Google Scholar