An electrostatic spray pyrolysis method (ESD) was applied for the preparation of a dense, continuous and crack-free thin film of gadolinia-doped ceria (Ce0.9Gd0.1O2-delta, CGO) on pure YSZ ((ZrO2)(0.92)(Y2O3)(0.08)) substrate for intermediate temperature solid oxide fuel cell (IT-SOFC) applications. ToF-SIMS depth profiles and XRD were performed to characterize the possible interfacial reactivity. No reaction was detected between CGO layer and YSZ substrate after heat treatment at 800 degrees C for 2 h in air. After heat treatment at 1500 degrees C during 10 h in air a (YSZ)(1-x)(CGO)(x) solid solution was detected in homogeneous composition at least over 6 pm in thickness. No differences were observed between the impedance spectra of YSZ reference, the CGO/YSZ bi-layer and the solid solution. (C) 2013 Elsevier B.V. All rights reserved.