Synthesis and characterization of new composite ceramics based on gadolinium-doped ceria and magnesia nanoparticlesWednesday (26.09.2018) 10:45 - 11:00 S1/03 - 223 Part of:
Despite they have been investigated for more than a century , electrolyte materials limit the broad use of solid oxide fuel cells (SOFCs). A new possibility to obtain materials with high oxygen ion conductivities offers the work of Kosacki et al. . They found that the grain boundaries between electrolyte and isolator particles can have even higher ionic conductivities than the electrolyte. Here we describe a novel approach how to make use of this unusual high boundary layer conductance. Due to its high ionic conductivity, GDC has been chosen as the electrolyte candidate .
Results and Discussion
A self-propagating high temperature synthesis method  is used for the synthesis of both GDC and MgO nanoparticles. The nanoparticles have diameters between 10-20 nm and show a narrow particle-size distribution. No aggregation was observed.
The sample was then pressed and sintered. The XRD patterns show two pure phases (MgO and GDC) of the samples both before and after sintering. Compared to the wide peaks of the nanoparticles, the narrowing of the peaks of the ceramic sample indicates the growth of crystallites during the sintering. The TEM and TEM-EDX characterization of the composite ceramic also manifest larger domains than the disperse nanoparticles before sintering.
Using the self-propagating high temperature synthesis method, GDC and MgO nanoparticles with diameters of about 10 nm can be synthesized with narrow particle-size distribution and no aggregation . Although the particle domains in the sintered ceramic are enlarged, they are still in the nanometer range.