Enhancement of oxygen surface exchange at the hetero-interface of (La,Sr)CoO(3)/(La,Sr)(2)CoO(4) with PLD-Layered films

The preferential site for oxygen isotope exchange was investigated on layered films of La(2-x)Sr(x)CoO(4) (x=0.5,1.0)/La(0.6)Sr(0.4)CoO(3) prepared by pulsed laser deposition (PLD) on a polycrystalline Ce(0.9)Gd(0.1)O(1.95). An isotope exchange experiment was performed at 773 K in (18)O-enriched oxygen of 0.2x10(5) Pa. Three-dimensional imaging of secondary ion mass spectrometry (SIMS) was carried out to visualize the isotope distribution. The SIMS images suggested that there are fast oxygen-incorporation paths along the hetero-phase interface of La(2-x)Sr(x)CoO(4)/La(0.6)Sr(0.4)CoO(3). The results have reproduced our former findings on the fast oxygen surface exchange with La(2-x)Sr(x)CoO(4)/La(0.6)Sr(0.4)CoO(3) composite polycrystals. (C) 2008 The Electrochemical Society.