Zirconium Oxide Structure Prepared by the Sol–Gel Route: I, The Role of the Alcoholic Solvent

Abstract

Sol-gel-derived powder samples of zirconia (ZrO 2 ) prepared via the dissolution of zirconium n-propoxide in methanol, ethanol, and 2-propanol have been characterized mainly using perturbed angular correlations spectroscopy, as a function of temperature. Results indicate that the nanostructures and subsequent thermal evolution are alcohol dependent: the shorter the alcohol chain, the more hydrolyzed the product. ZrO 2 powder that has been obtained using ethanol as the solvent is the product that exhibits the better stabilization of the metastable tetragonal phase (t-phase). It undergoes a clear and detailed t 1 -form 3 t 2 -form 3 monoclinic ZrO 2 thermal transformation and shows the highest activation energy against the transformation to the monoclinic phase.

Effect of preparation conditions on structural and catalytic properties of lithium zirconate

“…The precipitation is completed when the equivalence point (pH¼ 9) is reached. Caracoche et al [46] suggested that slight acidification of the solution of alkoxides by nitric acid induces the shift of zirconia crystallization to low-temperature region. This data is in crystallization of the metastable zirconia in acidic medium due to the excess free energy [47].…”

Thermal and crystallization behaviour of 8YSZ–CeO2 system

“…At 728 K a sharp exothermic effect with an enthalpy Q of 111.3 J/g was detected. This effect corresponds to the phase transition of the material from the amorphous to crystalline state [23][24][25]. At temperatures higher than 873 K, no exothermal effects were detected.…”

“…During heating from 873 to 1508 K, the mass of the sample continued to decrease but the mass loss was negligible (0.86%). This can be associated with the elimination of the residual OH groups from the material [25,26]. After annealing at temperatures higher than T S = 1508 K, the mass remained constant.…”

“…This temperature T S appears to be the temperature of stable solid solution formation. The precise value of T S was determined based on the method described in [25].…”

Synthesis of Lithium-doped Zirconia Nanoceramics of Controlled Oxygen Vacancies

“…1, January 2007, pp. [41][42][43][44][45][46] 2007, DESIDOC 41 cationic doping using hydrothermal processes, and sol-gel processes [5][6][7] .…”