APPLICATION OF HIGH-TEMPERATURE ELECTROCHEMICAL TECHNIQUES TO YBA2CU3O7-Y

High temperature solid-state electrochemical techniques have been applied by interfacing YBa2Cu3O7-y (YBCO) with solid-state ionic materials to modify, monitor, control, and optimize the properties of ceramic superconductors. Precise and optimal control of oxygen content as well as the determination of oxygen nonstoichiometry and the phase-stability diagram in the Y-Ba-Cu-O superconducting system have been investigated by a combination of electrochemical titration and oxygen sensing in solid-state cells. Significant texture-enhancement has been observed in the electrochemically treated YBCO disks such that the basal planes are preferentially oriented normal to the oxygen titration direction. However, the response of YBCO to this texturing is extremely powder specific, and appears closely related to the materials response to grain growth and densification in normal sintering. By incorporating grains with plateletlike morphology with high aspect ratios as seed material into the matrix of fine-size reactive precursor, bulk samples with good texture can be produced by the combined effect of temperature and electrochemical potential.