Silver-Enhanced Synthesis of YBa2Cu3O7-x

Abstract
Formation of the high-T c superconducting oxide YBa2Cu3O7-x via Y2BaCuO5+3BaCuO2+2CuO →2YBa2Cu3O7-x was found to be greatly accelerated by silver (Ag). As an example, for calcination at 900°C for 1 h, the fractional conversion was almost tripled with an addition of 2% (by weight) Ag in the reactant powders. Furthermore, for the calcined powders showing similar extents of the reaction, both the Meissner effect and T c (up to 95 K) increased with the Ag content. DTA studies established that the temperature at which the maximum reaction rate occurred was significantly lowered due to the presence of Ag.