The YSZ coatings with nanoctystalline columnar structure were prepared by magnetron sputtering and then dip-coated by a Fe-containing sol. The elements from sol decomposition products were diffused at 600 degrees C for 2 h to modify the columnar grain boundaries. The electrical conductivities of Fe-modified YSZ coating are predominantly ionic and 6-7 times higher than those of the as-deposited coating. The electrical conductivity increment is explained on the scavenging effects of diffused Fe2O3 on the intergranular siliceous phase based on the fact that a strong segregation of Fe and Si into the triple grain junctions is verified by EDS analysis. (C) 2014 Elsevier B.V. All rights reserved.