High ionic conductivity in ultrathin nanocrystalline gadolinia-doped ceria films

High ionic conductivities were observed in ultrathin nanocrystalline gadolinia-doped ceria (GDC) films with thicknesses comparable to the grain size (20-50 nm). Conductivities were determined to be effectively three to four orders of magnitude higher relative to those of thicker films (> 500 nm). The distinct properties in ultrathin GDC films were attributed to the reduction of cross grain boundary resistance and the segregation of the Gd dopants in the vicinity of grain boundaries. (c) 2006 American Institute of Physics.