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Consecutive inert and oxygen atmosphere sintering in the synthesis of LaBa2Cu3Oy with T(R = 0)>90 K

Published online by Cambridge University Press:  31 January 2011

M. H. Ghandehari
Affiliation:
Unocal Science and Technology Division, 376 South Valencia Avenue, Brea, California 92621
S. G. Brass
Affiliation:
Unocal Science and Technology Division, 376 South Valencia Avenue, Brea, California 92621
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Abstract

Combinations of inert atmosphere sintering and oxygen atmosphere sintering have previously been reported as necessary for the synthesis of LaBa2Cu3Oy superconductors which achieve zero resistance at temperatures above 90 K. Sintering under oxygen atmosphere only is known to produce La(1+x)Ba(2−x)Cu3Oy, in which La is substituted for Ba in the crystal lattice. The latter substituted compounds achieve zero resistance at temperatures well below the boiling point of liquid nitrogen. In this work, we show that during the initial inert atmosphere sintering step, LaBa2Cu3Oy powder decomposes, in part, into several intermediate compounds. These compounds are then recombined in the subsequent oxygen atmosphere sintering step to form LaBa2Cu3Oy, which achieves zero resistance at temperatures above 90 K. We propose that the net effect of these two processing steps is to inhibit the substitution of La for Ba in the lattice of the fully processed material.

Type
Articles
Copyright
Copyright © Materials Research Society 1989

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References

REFERENCES

1Meng, R. L.Hor, P. H.Wang, Y. Q.Juang, Z. J.Sun, Y. Y.Gao, L.Betchold, J. and Chu, J. C.Extended Abstracts High Temperature Superconductors II, Reno, NV, pp. 233235, April 1988.Google Scholar
2Wada, T.Suzuki, N.Maeda, T.Maeda, A.Uchida, S.Uchinakura, K. and Tanaka, S.Appl. Phys. Lett. 52, 1989 (1988).CrossRefGoogle Scholar
3Brass, S.G. and Ghandehari, M.H.Appl. Phys. Lett. 53, 2235 (1988).CrossRefGoogle Scholar
4Song, Y.Golben, J. P.Chittipeddi, S. and Gains, J. R.Phys. Rev. B 38, 4605 (1988).CrossRefGoogle Scholar
5Brass, S. G. and Ghandehari, M. H.Appl. Phys. A 48, 401 (1989).CrossRefGoogle Scholar
6denotes the oxygen stoichiometry of this compound. The oxygen content of the sample, as quenched from the inert atmosphere, was not measured.Google Scholar
7Michel, C.Rakho, L. Er, and Raveau, B.Solid State Chem. 39, 161 (1981).CrossRefGoogle Scholar
8Kilbanow, D.Sujata, K. and Mason, T. O.J. Am. Ceram. Soc. 71, C267 (1988).Google Scholar
9Segre, C.U.Dabrowski, B.Hinks, D. G.Zhang, K.Jorgensen, J.D.Beno, M. A. and Schuller, I. K.Nature 329, 227 (1987).CrossRefGoogle Scholar