AN IMPROVED PROCEDURE FOR DETERMINING OXYGEN-CONTENT IN HIGH-T-C COPPER OXIDES

We present an improved double titration method for high-T-c supercondu ctors, in which the major step is adding KSCN as an indicator of the e nd point after the starch end point. By adding it, a greater amount of Na2S2O3 solution can be added after the starch end point, at least 0. 12 ml. We found that adding KSCN can lead to precise measuring results and reduce the experimental error. The oxygen contents of two series of superconductors were determined by this approach. For YBa2Cu3Oy, th e errors are Delta p similar to 0.003 and Delta y similar to 0.005, wh ich are lower than that of other reports.