Abstract
Solid oxide fuel cells require electrolyte materials that combine high oxide-ion conductivity with suitable sintering behavior, thermomechanical compatibility, and structural stability. This study presents a comparative investigation of the structural, thermomechanical, and electrical properties of nanosized yttria-stabilized zirconia (YSZ), scandia-stabilized zirconia (ScSZ), and gadolinium-doped ceria (GDC) powders synthesized by laser evaporation under consistent processing conditions. Phase composition, specific surface area, and particle morphology were characterized by X-ray diffraction, nitrogen adsorption, and transmission electron microscopy. Sintering behavior and linear thermal expansion were investigated by dilatometry, while electrical conductivity was measured using a four-probe direct-current method. All three compositions formed single-phase cubic fluorite-type solid solutions. The average particle sizes were 15.5 nm for YSZ, 10.8 nm for ScSZ, and 24.2 nm for GDC. YSZ exhibited the highest onset temperature of shrinkage but the most intensive subsequent densification, whereas GDC began to shrink at a lower temperature and densified more gradually; ScSZ showed intermediate behavior. The coefficients of thermal expansion were 11.0 * 10-6 , 11.3 * 10-6 , and 12.7 * 10-6 K -1 for YSZ, ScSZ, and GDC, respectively. At 800 C, the electrical conductivity reached approximately 0.04, 0.11, and 0.09 S cm -1, respectively. Comparison with a lanthanum strontium manganite/yttria-stabilized zirconia cathode composite indicated favorable shrinkage matching for ScSZ under the investigated cosintering conditions. The results demonstrate that electrolyte selection should simultaneously consider electrical conductivity, densification behavior, and thermomechanical compatibility, with ScSZ showing a particularly favorable balance of these properties under the investigated conditions.