10 mol% gadolinium-doped cerium (IV) oxide was prepared by solid-state reaction route and deposited as a thick film using thermal (plasma) spray technique. The phase development, microstructure and topography were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The mechanical strength of the deposited film was determined by pull-off adhesion test. The plasma-sprayed GDC was characterized for its electrical properties by dc four-probe conductivity experiments. The maximum conductivity for plasma-sprayed GDC was found to be 3.60 × 10−2 Scm−1, which was lesser than 2.25 × 10−1 Scm−1 for the CIP-sintered GDC at 1000 oC and pO2 = 0.21 atm. The decrease in the conductivity is attributed to the larger intergranular spaces and uneven networking observed in the microstructure resulted in higher activation energy and low conductivity.

Keywords: Thermal spray coating, GDC, Electrolyte, Ionic conductivity