Effect of Ho addition on the properties of Y-system superconductors
- 14 Downloads
(YHo)Ba2Cu3O7−y is prepared by the powder melting process and its properties are investigated. It is found that Ho addition can change the melting temperature of a Y-system superconductor. TheJ c values of YBCO can be improved by Ho substitution, which is due to the effect of Ho addition on the number and quality of grain boundaries and the size and distribution of 211 particles. The highestJ c value was found to be 50,000 A/cm2 (77 K, 1T,H⊥I) in Y0.8Ho0.2Ba2Cu3O7−y. Our results indicate that the number and quality of grain boundaries have a great influence on the superconducting properties. A discussion is given on the relationship betweenJ c and the size and phase proportion of 211 particles. There are a lot of dense twins in the sample, and many crystal defects exist around the 211 phase.
Key wordsYBCO Ho addition critical current density
Unable to display preview. Download preview PDF.
- 1.J. G. Bednorz and K. A. Muller,Z. Phys. B 64, 189 (1986).Google Scholar
- 2.S. Jin, T. H. Tiefel, R. C. Sherwood, M. E. Davis, R. B. Van Dover, S. W. Kammlott, R. A. Fastnacht, and H. D. Keith,Appl. Phys. Lett. 52, 2074 (1988).Google Scholar
- 3.K. Salama, V. Selvamanickam, L. Gao, and K. Sun,Appl. Phys. Lett. 54, 2352 (1989).Google Scholar
- 4.M. Murakami, M. Morita, and N. Koyama,Jpn. J. Appl Phys. 28, 1189 (1989).Google Scholar
- 5.Zhou Lian, Zhang Pingxiang, Ji Ping, Wang JinRong, Wang Keguang, and Wu Xiaozu, Proceedings of the 1990 Applied Superconductivity Conference.Google Scholar
- 6.E. Yanagisawa and K. Kase, private letter.Google Scholar