IONIC SUPERCONDUCTOR OBTAINED BY INTRODUCTION OF LITHIUM ATOMS IN THE LATTICE OF HIGH TEMPERATURE SUPERCONDUCTOR MATERIALS OF THE BA2YCU3O7-X TYPE

摘要

The invention discloses a new ceramic superconductor material of formula LizBa2TRCu3O7-x wherein TR is an element or mixture of elements of rare earthes and wherein copper may be partially substituted by Fe, Co, Ni or Al. This material whose the transition temperature is equal to that of ''Ybacuo'' (Ba2TRCu3O7-x) from which it was obtained, has nonetheless the particularity of presenting at higher temperature ( APPROX 340 K) a cationic conductivity. In order to obtain this material, the ''ybacuo'' is first prepared by sintering, in an oxigen atmosphere, a stoichiometric mixture of the oxides or salts of Cu, Ba and Y (or other lanthanide). Once the ''ybacuo'' is obtained, it is treated with a solution of an organolithium (butyl-lithium) in an appropriate organic solvent (cyclohexane), the amount of lithium introduced in the lattice depending essentially on the duration of the reaction.