Electrochemical Response of YBa²cu³0⁷_^x as a Function of Oxygen Content

By varying the oxygen content in the high temperature superconductor phase YBa²Cu³⁰⁷-x(0 < X < 1), the electrical properties of this material can be manipulated from that of a superconductor to that of an insulating semiconductor. In this paper, a method for preparing YBa²Cu³0⁷-^x samples with different oxygen contents is described and a corresponding procedure for fabricating electrodes from these samples is outlined. The described procedure provides a simple and systematic means to tailor the conductive properties of electrode specimens. The electrochemical responses of the variable oxygen content electrodes are examined by cyclic voltammetry under conditions where the host electrodes are stable. Furthermore, the voltammetry recorded at these high temperature superconductors is used to assess the surface quality and thereby determine the degree of reversibility of electron transfer at superconductor/solution interfaces. The ability to control the density of states within these electrode specimens and thereby examine the effects this quantity has on the heterogeneous charge transfer rate is also addressed.