Solid State Ionics, Vol.286, 19-23, 2016
Determination of oxygen surface exchange constant of LaNi0.6Fe0.4O3-delta coated with Ce0.9Gd0.1O1.95 by isotope exchange technique
The surface oxygen exchange coefficient (le) of LaNia(6)Fe(0.4)O(3-delta) (LNF) coated with porous Cea(9)Gd(0.1)O(1.95) (GDC) was determined by the isotope exchange technique. The LNF coated with GDC was subjected to isotope exchange treatment where O-16(2) was abruptly changed into 1802 at a range temperature of 873-1073 K under 10(-1) and 10(-2) bar of the oxygen partial pressure (p(O-2)). The line -scanning mode of secondary ion mass spectrometry was used to determine the surface oxygen exchange of the LNF coated with GDC. The k* of LNF coated with GDC is enhanced compared to that of the bare LNF due to the formation of triple phase boundary between LNF, GDC, and gas phase of oxygen. The role of GDC is enhancing the incorporation process of the oxygen dissociated at the LNF surface. The adsorption and dissociation of oxygen takes place at LNF surface and incorporated into GDC porous. (C) 2015 Elsevier B.V. All rights reserved.