AVS 50th International Symposium
    Applied Surface Science Wednesday Sessions
       Session AS-WeA

Paper AS-WeA1
Development of Multi Layered Oxide Nanofilms for Fast Oxygen Ionic Conduction

Wednesday, November 5, 2003, 2:00 pm, Room 324/325

Session: Fuel Cell & Battery Materials/Corrosion
Presenter: S. Thevuthasan, Pacific Northwest National Laboratory
Authors: S. Thevuthasan, Pacific Northwest National Laboratory
S. Azad, Pacific Northwest National Laboratory
O.A. Marina, Pacific Northwest National Laboratory
C.M. Wang, Pacific Northwest National Laboratory
V. Shutthanandan, Pacific Northwest National Laboratory
L.V. Saraf, Pacific Northwest National Laboratory
D.E. McCready, Pacific Northwest National Laboratory
I. Lyubinetsky, Pacific Northwest National Laboratory
A. El-Azab, Pacific Northwest National Laboratory
C.H.F. Peden, Pacific Northwest National Laboratory
Correspondent: Click to Email
There has been considerable interest in solid oxide fuel cell (SOFC) devices since they provide relatively clean alternative energy to the conventional fossil fuels. Several research groups are working on developing electrolyte materials with higher oxygen ionic conductivity at low temperatures to improve the efficiency of SOFC device at low temperatures. It is well known that nanoscale materials often display properties very different from the base coarse-grained bulk materials. In particular, it has been recently demonstrated that a nanoscale lamellar structure of two different fluorides (calcium fluoride and barium fluoride) can exhibit significantly higher ionic conductivity along the interfacial directions at moderate temperatures.@footnote 1@ If such a remarkable finding could be transferred into practice, it would provide the ability to design similar structures from oxygen ion conductors to enhance the performance of SOFC devices at temperatures substantially lower than the current operating temperatures. In this study, we investigated the effect of multiple interfaces on oxygen ionic conductivity in Gd-doped single crystal ceria/zirconia multi layers as a function of Gd concentration. Pure and Gd-doped ceria and zirconia films were grown by oxygen plasma assisted molecular beam epitaxy (OPA-MBE) and characterized by reflection high-energy electron diffraction (RHEED), x-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS) and high-resolution transmission electron microscopy (HRTEM). The preliminary results are encouraging and four layered Gd-doped ceria/zirconia multi layered structure shows higher oxygen ionic conductivity compared to two layered structures. @FootnoteText@ @footnote 1@N. Sata, K. Eberman, K. Eberl and J. Maier, Nature 408 (2000) 946.