Abstract
The superconducting properties of Y1−y Ca y Sr2Cu2GaO7−δ have been examined and related to the Ca content,y, and the use of annealing treatments at 350 bar oxygen. Superconductivity withT c up to 41 K was found only for high-pressure-annealed samples, and the structural effects of Ca substitution and high-pressure treatment were examined using powder neutron diffraction. Small but significant changes in Cu-Cu and Cu-O distances were found and suggest that the Cu ions are more highly charged in superconducting samples. Partial substitution of Ba for Sr was found to be possible (up to 20%) to give samples which, after annealing in high-pressure oxygen, were superconducting at temperatures up to 68 K.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
A. Ono, T. Tanaka, H. Nozaki, and Y. Ishizawa,Jpn. J. Appl. Phys. 26, L1687 (1987).
B. W. Veal, W. K. Kwok, A. Umezawa, G. W. Crabtree, J. D. Jorgensen, J. W. Downey, L. J. Nowicki, A. W. Mitchell, A. P. Paulikas, and C. H. Sower,Appl. Phys. Lett. 51, 279 (1987).
S. A. Sunshine, L. F. Schneemeyer, T. Siegrist, D. C. Douglas, J. V. Waszczak, R. J. Cava, E. M. Gyorgy, and D. W. Murphy,Chem. Mater. 1, 331 (1989).
P. Karen, H. Fjellvag, A. Kjekshus, and A. F. Andresen,J. Solid State Chem. 92, 57 (1991).
A. K. Ganguli and M. A. Subramanian,Mater. Res. Bull. 26, 869 (1991).
B. Okai,Jpn. J. Appl. Phys. 29, L2180 (1990).
P. R. Slater and C. Greaves,Physica C 180, 299 (1991).
T. Den and T. Kobayashi,Physica C 196, 141 (1992).
T. G. N. Babu and C. Greaves,Physica C 207, 44 (1993).
G. Roth, P. Adelmann, G. Heger, R. Knitter, and Th. Wolf,J. Phys. 1, 721 (1991).
J. T. Vaughey, J. P. Thiel, E. F. Hasty, D. A. Groenke, C. L. Stern, K. R. Poeppelmeier, B. Dabrowski, D. G. Hinks, and A. W. Mitchell,Chem. Mater. 3, 935 (1991).
Q. Huang, R. J. Cava, A. Santoro, J. J. Krajewski, and W. F. Peck,Physica C 193, 196 (1992).
T. G. N. Babu, J. D. Kilgour, P. R. Slater, and C. Greaves,J. Solid State Chem. 103, 472 (1993).
S. Adachi, K. Kubo, S. Takano, and H. Yamauchi,Physica C 191, 174 (1992).
B. Dabrowski, P. Radaelli, D. G. Hinks, A. W. Mitchell, J. T. Vaughey, D. A. Groenke, and K. R. Poeppelmeier,Physica C 193, 63 (1992).
V. P. Dravid and H. Zhang,Physica C 200, 349 (1992).
J. C. Matthewman, P. Thompson, and P. J. Brown,J. Appl. Crystallogr. 15, 167 (1982).
P. J. Brown and J. C. Matthewman, Rutherford Appleton Laboratory Report RAL-87-010 (1987).
I. D. Brown and D. Altermatt,Acta Crystallogr. B 41, 244 (1985).
T. G. N. Babu and C. Greaves, submitted toPhysica B 194–196, 2105 (1994).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Babu, T.G.N., Greaves, C. Synthesis, composition, and structure of superconducting (Y, Ca)Sr, Ba)2Cu2GaO7−δ . J Supercond 8, 21–25 (1995). https://doi.org/10.1007/BF00732236
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00732236