Morphology control of Ce_0.9Gd_0.1O_1.95 nanopowder synthesized by sol-gel method using PVP as a surfactant

In this work, well-dispersed nanopowder of Ce_0.9Gd_0.1O_1.95 (gadolinia doped ceria, GDC) was synthesized by a novel sol-gel thermolysis method using a combination of citrate acid and polyvinylpyrrolidone (PVP). PVP performed as a surfactant and its amount was optimized in terms of GDC powder morphology. The physical and chemical properties of the resultants were characterized by XRD, TG/DTA, FT-IR, SEM, BET and PSA. From the XRD patterns, well-crystalline cubic fluorite structured GDC was obtained after calcining the precursor at 600 °C. The SEM observation showed an average particle size of about 15 nm for the optimal GDC powder and particle size analysis (PSA) gave a narrow distribution of particle size. The sintering experiment showed a good sinterability and a relative density of 94% was achieved at 1300 °C. The dense sample exhibited an ionic conductivity of 0.017 S cm^-1 at 600 °C in air.