Preparation of Yttria‐Stabilized Zirconia Microtube by Electrochemical Vapor Deposition

A microtube of yttria‐stabilized zirconia of ca. 100 μm diameter was prepared. An yttria‐stabilized zironia film was formed over a surface‐oxidized nickel wire with a diameter of 10 μm by electrochemical vapor deposition using zirconium tetrachloride and yttrium trichloride as metal sources, and nickel oxide as an oxygen source for the reaction. The YSZ‐coated wire was then immersed in aqueous 11.5 mol.L ‐1 hydrochloric acid to dissolve the nickel and nickel oxide, and a microtube of 80 mol? yttria‐stabilized zirconia with a cubic crystal structure was obtained. The surface of the microtube was rough, but was pinhole‐free, from SEM observation. The thickness of the zirconia layer was about 3 μm.