Sol–gel synthesis and phase composition of ultrafine ceria-doped zirconia powders for functional ceramics

Ultrafine ceria-doped zirconia powders with the general formula CexZr1−xO2 oriented for functional ceramic materials for different purposes were prepared by modified sol–gel synthesis with use of monoethanolamine or tetraethylammonium hydroxide. All powders were high crystallized single-phase systems with average crystallite size 8–11 nm. It was established that doping of zirconia by ceria led to a decrease in the crystallite size. At the same time the nature of the zirconium salt anion has little effect on crystallite size. However, only powders obtained from zirconyl chloride had crystallites with sizes below 10 nm. When x = 0.150–0.155, a sharp increase in the crystallite size was observed regardless of the used organic components. Use of tetraethylammonium hydroxide resulted in formation of CexZr1−xO2 crystallites of 2–3 nm smaller than that which was obtained in the presence of monoethanolamine.