The use of low‐energy SIMS (LE‐SIMS) for nanoscale fuel cell material development

Abstract

Low-energy secondary ion mass spectrometry has been used to investigate the matrix structure and interface attributes of a novel Ce 0.85 Sm 0.15 O 2 /CeO 2 multilayer fuel cell material. Nanoscale oxide systems have shown enhanced ionic conductivities when produced to form highly oriented epitaxial structures. The Sm-doped CeO 2 material system is of particular interest for fuel cell technology because of its inherently high ionic conductivity at low operating temperatures (600-800• C). For this study, a nanometer-scale Ce 0.85 Sm 0.15 O 2 /CeO 2 multilayer was grown by pulsed laser deposition. The sample was annealed at 700• C in an oxygen ambience. High-resolution, low-energy depth profiling using Cs revealed some diffusion of the multilayer structure after annealing, along with a possible volume change for the Sm-doped layers. Changes in layer volume will lead to an increase in the mechanical strain and may cause the material to crack. The findings presented here suggest that the Ce 0.85 Sm 0.15 O 2 /CeO 2 multilayer structure in its current form may not possess the level of thermal stability required for use within a fuel cell environment.