The Oxygen Permeation Properties of Nanocrystalline CeO2 Thin Films

The measurement of oxygen flux across nanocrystalline cerium oxide (CeO2) thin films at intermediate temperature (650-800 degrees C) is presented. Porous ceria support substrates were fabricated by sintering with carbon additions. The final dense film was deposited from an optimized sol-gel solution resulting in a mean grain size of 50 nm, which displayed oxygen flux values of up to 0.014 mu mol/cm(2) s over the oxygen partial pressure range from air to helium gas used in the measurement at 800 degrees C. The oxygen flux characteristics confirm mixed ionic and electronic conductivities in nanocrystalline ceria films and demonstrate the role of size dependent materials properties as a design parameter in functional membranes for oxygen separation. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3503519] All rights reserved.