A series of monodisperse sub-micron spherical zirconia solid solutions were prepared by hydrolysis of zirconium, aluminum, nickel and copper salts in ethanol. The heat-treatment process of the as-prepared amorphous materials in air atmosphere at 500 1C leaded to the production of the zirconia solid solutions in tetragonal phase. Further heating from 800–1400 1C resulted in the formation of stabilized monoclinic zirconia solid solutions. X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy confirmed the formation of pure phase nanocrystalline zirconia solid solutions with spherical shape even at 1000 1C. Optical studies of the nanostructured solid solutions showed the decreases in band gaps with increasing the heat-treatment temperature due to grain growth.
