An accurate method of iodometric titration for determining oxygen content of superconducting cuprates

Abstract

There are three problems existing in double iodometric titration. First, the calculating equation is too rough to obtain accurate results. Second, an error comes from iodine adsorbed by CuI. Third, when a sample is doped with iron-like elements, iron interferes with this method. The above problems were solved as following. We adopted a new equation, which may modify copper valence p by 4% and oxygen content by 0.02. To reduce the experimental error KSCN was added to displace the adsorbed iodine on the CuI. NH 4HF 2 was introduced to prevent the interference of Fe. Our experiment results show that by adding NH 4HF 2 the modification of oxygen content increases when Fe content increases.