Mass Transport in Oxide Thin Films - Visualization and Control

Abstract

Experimental results obtained on electrochemical cells of the form PCO/YSZ/Ag by a novel experimental technique capable of simultaneously performing in situ optical absorption and electrochemical impedance spectroscopy (EIS) measurements under bias were used to demonstrate the ability to extract and control nonstoichiometry in thin film oxides. We showed, that when applied to model materials systems such as PrxCe1-xO2-δ (PCO), these techniques are capable of deriving a detailed picture of the defect equilibria and transport properties of such materials and determining whether, and to what degree, they differ from bulk properties. Key studies of chemical capacitance, optical absorption and color front motion kinetics are used to extract key thermodynamic and kinetic (kex, DO) parameters in PCO.