Influence of galia (Ga2O3) addition on the phase evolution and grain growth behavior of voided yttria stabilized zirconia (YSZ) powder

The effect of a galia (Ga2O3) addition on the crystallographic phase transformations and the grain growth behavior of yttria stabilized zirconia (YSZ) were investigated regarding powders containing different amounts of galia in the range of 0–25 mol %. Ternary compositions of galia- YSZ sponge-like cryogels were prepared by the sol-gel method combining freeze-drying process and calcination of dried powders at different temperatures for 2 h in air. Crystallographic phase transitions were analyzed via X-ray diffraction (XRD) and exceptional powder particle morphology of internal nano voids derived from the freeze-drying technique was investigated by using Scanning Transmission Electron Microscope (STEM). It was shown that galia supressed the grain growth process in yttria stabilized zirconia and had no effect on the internal voids obtained.