The preparation and characterization of Al2O3/ZrO2 nanocrystalline composite by a simple gel method

Al2O3–ZrO2 nanocomposite was prepared in tartaric, glycolic and citric acids by a simple gel method. The surface areas of the samples were changed from 58 m2/g to 278 m2/g. The average crystallite size of nanocomposite heat treated at 1000 °C was less than 10 nm and also tetragonal zirconia phase without transformation to monoclinic phase, which remained in the alumina matrix close to 1500 °C according to X-ray results. However, monoclinic phase was observed from Raman spectra of samples heated at 1500 °C. The prepared gel and subsequent heat-treated powders were characterized by X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM) to get detailed information regarding differentiation of polymorphs of zirconia as well as formation of powders.