Synthesis of Metastable Tetragonal (t′) ZrO ₂ ‐12 mol% YO _1.5 by the Organic Polymerized Complex Method

Zirconia‐yttria (ZrO ₂ ‐12 mol% YO _1.5 ) powders were prepared via an organic polymerized complex method that was based on the Pechini‐type reaction route. A mixed solution of citric acid, ethylene glycol, and zirconium and yttrium ions were polymerized to form a transparent resin, which then became a black powder after charring at ∼450°C. This product was used as a precursor for ZrO ₂ ‐12 mol% YO _1.5 . The formation of a metastable tetragonal ( t ´) phase with compositional homogeneity occurred when the precursor was heated at the rate of 10°C/min up to a temperature >560°C. X‐ray diffraction peaks became sharp with an increase in the heat‐treatment temperature. A t ´‐form with cell parameters of a = 5.1265(6) Å and c = 5.1559(9) Å were obtained via heat treatment up to 1400°C. This study shows that the organic polymerized complex method is effective for obtaining the compositionally homogeneous metastable t ´‐form in the ZrO ₂ ‐YO _1.5 system for short annealing times at relatively lower temperatures.