Electrochemical Treatment on Bulks of Bi₂Sr₂CaCu_8+z System

Abstract

The electrochemical reduction was tried for Bi_2.2Sr_1.8CaCu₂0_8+z pellet in 0.01N AgNO₃ and CuSO₄ ⋅5H₂O in methanol with silver and copper as the counter electrode. The resistance decreased by Ag particle deposition at the grain boundaries, and its decrease brought about the enhancement of Tco. Bi-2212 sample was reduced by Ag to about 0.24 mole fraction and by Cu to about 0.07 mole fraction. Tco was enhanced by 4K for the former and Tc(onset) was enhanced by 5K for the latter. The oxygen content of each sample was determined by ordinary iodometric titration