Ba-K-Bi-O和Ba-K-Pb-O氧化物的碘量滴定

Iodometric Titration of Ba-K-Bi-O and Ba-K-Pb-O Oxides

本文提出了碘量法滴定Ba－K－Bi-O和Ba－K－Pb－O氧化物中Ba和Pb的名义价态，然后据此计算这些氧化物中K和Ba含量的方法。该法适用于正常条件下合成的具有ABO3型钙钛矿结构的Ba－K－Bi-O和Ba－K－Pb－O晶体。用本法的滴定结果表明，Tc为31K的Ba－K－Bi-O超导体的K含量为0．4，当K含量减少时，Tc随之下降。

A method of iodometric titration has been used to determine the nominal valenceof Bi and Pb in Ba-K-Bi-O and Ba-K-Pb-O oxides. The contents of Ba and K in these oxidescan also be calculated according to the nominal valences. This method is suitable for theanalysis of Ba-K-Bi-O and Ba-K-Pb-O crystals, which are prepared under normal syntheticconditions and have ABO, type perovskite structure. Results show that the K content is 0. 4for Ba-K-Bi-O superconductor with Tc = 31 K, and TC falls off as the K content is decreased.