Determination of the Stoichiometric Composition of High-Temperature Superconductors by ICP-OES for Production Control

 A procedure to dissolve and analyse different types of high-temperature superconducting materials in order to determine their stoichiometric com- position is described. As sample materials Y-Ba-Cu-O and (Pb)Bi-Sr-Ca-Cu-O were analysed. They were dissolved with hydrochloric acid and analysed by simultaneous ICP-OES, which fits best for this analytical task because of its multielement capacity, its high precision of determination and accuracy. Each of the relevant metals (Pb, Bi, Sr, Ca, Y, Ba, Cu) could be determined successfully. The precision of the determination was found to be better than 2% relative standard deviation and usually even below 1%. The sample preparation and determination procedure described allows a high sample throughput, which is essential for production control. Also precursors of the superconducting materials (e.g. nitrate solutions) could be analysed by the procedure described.