Development of A New Method for Measuring the Oxygen Content of the Oxide Superconductor YBa₂Cu₃O_y with a Dissolved Oxygen Sensor

Abstract

  For cuprate superconductors, the Cu valency is a determining factor of the superconducting transition temperature (T_c). The Cu valence (v) of the superconductor YBa₂Cu₃O_y (YBCO) has been calculated from oxygen content (y) by the charge neutralization rule. The conventional methods for measuring the oxygen content are iodometry and coulometry. Recently, we developed a novel oxygen measuring method for La_2-xSr_xCuO₄ that uses a dissolved oxygen sensor (the DO method). In this study, we examine whether the oxygen content of YBa₂Cu₃O_y can be determined by the DO method. The y value obtained by the DO method was compared with that obtained by the iodometric method. In addition, we developed a new correction method by applying the diffusion equation. After correction, the errors of v and y fit within 0.026 and 0.039, respectively. We found that DO method is effective for measuring the oxygen content of YBCO after correction.