ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 33, Number 3
JKCSEZ 33(3)
June 20, 1989 

Superconducting fiber of high Tc YBa2Cu3O7-δ was successfully prepared by the sol-gel method. The stoichiometric mixture of Y, Ba and Cu nitrates was dissolved in water, to which citric acid solution was added. Then ammonium hydroxide was added to the mixture in order to increase the pH to a value between 5.8 and 6.2. The mixture was heated carefully to form a homogeneous colloid sol at 358 K. The solution was viscous enough to draw a long gel fiber, which was then heated at 1223K for 8 hrs. under oxygen partial pressure of PO2 = 1 atm., cooled slowly and annealed at 723K for 13 hrs.. The reacted superconducting sample maintained a fiber form with some shrinkage of its volume. The superconducting transition temperatures (Tc, onset and Tc, offset) of YBa2Cu3O7-δ have been determined to be approximately 95K and 82K, respectively. The superconducting phase was also confirmed by Meissner effect at liquid nitrogen boiling temperature.