Aqueous tape casting and crystallization behavior of gadolinium-doped ceria

An aqueous tape casting of gadolinia-doped ceria (GDC) ceramics was developed using Poly(acrylic acid) PAA as dispersant, Poly(vinyl alcohol) PVA as binder, Poly(ethylene glycol) PEG as plasticizer, and deionized water as solvent. Surface properties of GDC powder with and without PAA dispersant were characterized by electrokinetic measurements. The zeta potential measurement revealed that the isoelectric point for GDC powders in the absence of dispersant corresponds to a pH value of 4.06. The experimental results showed that pH value greatly affects the rheology of the slurry. Homogeneous, smooth, and defect-free green tapes were successfully obtained by using an appropriate slurry formula. Moreover, the crystallization kinetics of GDC powders prepared by coprecipitation process also has been investigated in this study. The activation energy of crystallization was calculated by differential scanning calorimetry (DSC) at different heating rates. Analysis of non-isothermal DSC data presented values of 105.3 kJ/mol and 1.171 for the activation energy of crystallization presented and the Avrami exponent, respectively.