Mobility of Sr in Gadolinia Doped Ceria Barrier Layers Prepared Using Spray Pyrolysis, Pulsed Laser Deposition and Magnetron Sputtering Methods

Gadolinia doped ceria Ce0.9Gd0.1O2-δ (GDC) barrier layer was deposited onto YSZ electrolyte and Ni-YSZ|YSZ electrolyte half-cell using pulsed laser deposition (PLD), magnetron sputtering (MS) or spray pyrolysis (SP) methods. The first set of GDC barrier layers was studied without additional sintering and the second set was additionally sintered for 3 h at 1300°C. Sr mobility initiated by thermal treatment of La0.6Sr0.4CoO3-δ cathode at 950°C and 1100°C was systematically studied with the GDC layers prepared using PLD, MS and SP methods. Concentration profiles of Zr ion in GDC, Ce in YSZ, Sr in GDC and Sr in YSZ were recorded using TOF-SIMS analysis method. XRD and SEM methods were applied for the analysis of Sr mobility in the GDC layer and results were correlated with impedance, cyclic voltammetry and other electrochemical data. The influence of synthesis method and thermal treatment of the GDC layer on the Sr mobility was established. Changes in the microstructure of cathode|chemical barrier layer|electrolyte interfaces caused by the thermal treatment of the cathode as well as the GDC layer during the preparation (including sintering) steps have been demonstrated and discussed.