Non‐stoichiometry in Oxide Thin Films: A Chemical Capacitance Study of the Praseodymium‐Cerium Oxide System

• DOI: 10.1002/adfm.201202104
• Publication Date: 2012-11-26T09:55:16Z
• Authors: Di Chen; Sean R. Bishop; Harry L. Tuller
• Keywords: Stoichiometry; Cerium oxide; Partial pressure; Praseodymium

Abstract While the properties of functional oxide thin films often depend strongly on their oxygen stoichiometry, there have been few ways to extract this information reliably and in situ. In work, derivation non‐stoichiometry dense Pr 0.1 Ce 0.9 O 2−δ from an analysis chemical capacitance obtained by impedance spectroscopy is described. Measurements are performed electrochemical cells form /Y 0.16 Zr 0.84 1.92 /Pr over temperature range 450 800 °C partial pressure 10 −5 1 atm 2 . With aid a defect equilibria model, approximations relate directly non‐stoichiometry, without need for fitting parameters. The calculated allows extraction thermodynamic constants defining generation. General agreement these with bulk values derived thermogravimetric found, thereby confirming suitability technique measuring films. Potential sources error observed earlier studies perovskite structured also discussed.