Effect of titanium on yttria stabilized zirconia with constant Y2O3 content synthesized by a modified Pechini process

A modified Pechini process was used to synthesize compositionally well-defined Ti-doped 8YSZ nanopowders with a fixed yttrium content, controlled morphology and grain size. An organic/metal salts R ratio of 5 or 10 can lead to a tetragonal or cubic phase, respectively, after thermal treatments above 800 degrees C. For R = 5, an increasing content of Ti showed an enlarged tetragonality. Single cubic phase and dense materials of Ti-doped 8YSZ were obtained after a heat treatment above 1500 degrees C for 24 h and a cell volume decrease is due to the substitution of Zr4+ by Ti4+. Electronic microscopy was used to analyse the crystal size and shape. Electrochemical impedance spectroscopy experiments evidenced for a lower ceramic conductivity with the increase of the titanium content. For small titanium contents (<5 mol%), the conductivity is higher than 10(-2) S/cm at 900 degrees C which is compatible with SOC (Solid Oxide Cell) applications.