A-Site Cation Substitutions in Strained Y-Doped BaZrO3 Multilayer Films Leading to Fast Proton Transport Pathways

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• 作者：Carmela Aruta ; Chu Han ; Si Zhou ; Claudia Cantoni ; Nan Yang ; Antonello Tebano ; Tien-Lin Lee ; Christoph Schlueter ; Angelo Bongiorno
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：April 21, 2016
• 年：2016
• 卷：120
• 期：15
• 页码：8387-8391
• 全文大小：326K
• 年卷期：0
• ISSN：1932-7455

文摘

Proton-conducting perovskite oxides form a class of solid electrolytes for novel electrochemical devices operating at moderate temperatures. Here, we use hard X-ray photoelectron spectroscopy, scanning transmission electron microscopy, and density functional theory calculations to investigate the structure and elucidate the origin of the fast proton transport properties of strained ultrathin films of Y-doped BaZrO₃ grown by pulsed lased deposition on NdGaO₃. Our study shows that our BaZr_0.8Y_0.2O₃ films incorporate a significant amount of Y dopants, and to a lesser extent also Zr ions, substituting for Ba²⁺, and that these substitutional defects agglomerate forming columnar regions crossing vertically from the surface to the interface the entire film. Our calculations also show that, in regions rich in Y substitutions for both Zr and Ba, the proton transfer process involves nearly zero-energy barriers, indicating that A-site cation substitutions by Y lead to fast transport pathways and hence are responsible for the previously observed enhanced values of the proton conductivity of these perovskite oxide films.