Study of oxygen transport in Ba₂YCu₃O _7-δ using a solid-state electrochemical cell

Abstract

A solid-state electrochemical oxygen concentration cell with yttria-stabilized zirconia (YSZ) as electrolyte was employed to study oxygen transport in Ba2YCu3O7-δ. On one side of the YSZ [a single-crystal wafer oriented in the (100) plane], reference and counter electrodes were fabricated from sputtered Au. A ceramic pellet of Ba2YCu3O7-δ was pressed against the other side of the electrolyte. Using this cell, it was possible to electrochemically drive oxygen into and out of the Ba2YCu3O 7-δ oxide electrode under controlled conditions. Current versus time and open circuit potential recovery data were analyzed according to various models. The diffusivity of oxygen in 94% dense Ba2YCu 3O7-δ was estimated to ≃5×10-8 cm2 s-1 at 550 °C.