Synthesis of bulk and film YBa2Cu3O7−x high-temperature superconductor by the sol-gel method
- 91 Downloads
Bulk YBa2Cu3O7−x has been prepared by the sol-gel method using metal alkoxide and metal acetate as precursors and ammonia or ethylenediamine as complexing agent. The temperature of the transformation of the gel precursor to YBa2Cu3O7−x depended on the type of precursor and the agent used for adjusting the pH. The gel synthesized from precursor alkoxide gives YBa2Cu3O7−x at lower temperature (750‡C for 6 h) than with acetate. The gel synthesized by different metal acetates and ammonia produces YBa2Cu3O7−x at a lower temperature than the sample prepared from acetate and ethylenediamine. From X-ray diffraction studies it appears that a relationship exists between the reactivity of the gel and the orientation of the corresponding pellet. The preliminary results from a film prepared by painting the gel on alumina and yttria-stabilized zirconia are presented. A high sintering temperature (940‡C for 1 h) was found to be necessary for obtaining superconductor film. The reactions between YBa2Cu3O7−x and supports were reduced by using silver as buffer. The Ton of the film prepared on the modified alumina support was 91 K and Toff was 78 K.
KeywordsAlumina Ammonia Zirconia Material Processing Sinter Temperature
Unable to display preview. Download preview PDF.
- 5.B. C. Bunker, Diana, L. Lamppa, J. A. Voigt, US Pat. 4839339, 13 June (1989).Google Scholar
- 12.P. Baboiux, J. M. Tarascon, B. G. Badley, L. H. Greene, G. W. Hull, B. W. Meagher and C. B. Eom, Mater. Res. Soc. Symp. Proc. 99 (1988)Google Scholar
- 13.H. W. Zandbergen, in “Chemistry of Electronic Ceramic Materials”, edited by Peter K. Davies and Robert S. Roth, Proceedings of the International Conference on the Chemistry of Electronic Ceramic Materials, 17–22 August (1990) p. 309.Google Scholar
- 22.Submitted for publication.Google Scholar
- 23.A. C. Pierre, Ceram. Bull. 70 (1991) 1281.Google Scholar