Outreach Programs

Education Programs Technology Outreach Program International Programs Distinguished Lecturer Series International Center for Materials Research MRL Diversity Fellowship MRL Travel Fellowship

Intern: Solome Girma, SUNY at Stony Brook Mentor: Tobias Schaedler Faculty Supervisor: Carlos Levi Department: Materials

METASTABLE PHASE EVOLUTION IN YO 1.5 - TIO2 - ZRO2

Sandwiched between the anode and the cathode, solid oxide fuel cells (SOFC) rely upon a thin layer of an oxygen ion conducting electrolyte, conventionally Yittria stabilized Zirconia (YSZ). This translates into the ability to convert energy at high temperatures (800°C -1,000°C) in a very efficient and environmentally friendly way. In order to improve SOFC, new electrolyte materials have to be developed that exhibit higher ionic conductivity at lower temperatures. This research focuses on the evolution of metastable phases over a wide range of compositions centered about the pyrochlore phase in the TiO2 – YO3/2 – ZrO2 phase diagram. In addition, the effects of different phases and compositions on the ionic conductivity are studied. Precursor methods have been used to make powders of selected compositions, which are then pyrolysed and progressively heat-treated at higher temperatures until equilibrium at 1300°C is reached. The phases present and their microstructure are studied by X-ray diffraction and transition electron microscopy.

Return to the RISE 2004 project list