Soft X-ray Studies of Solid Oxide Fuel Cell Cathodes

Speaker: David Newby

When: May 20, 2014 (Tue), 01:00PM to 02:00PM (add to my calendar)
Location: SCI 352

This event is part of the Departmental Seminars.

Dissertation Committee: Kevin Smith, Karl Ludwig, Robert Carey, Soumendra Basu, Xi Lin.

The electronic and chemical properties of heteroepitaxial thin films of LSCF-6428 grown on NGO have been studied using soft x-ray photoelectron spectroscopy. Specifically, the effect of annealing the films in low partial pressures of oxygen and argon has been investigated. We find that atmospheric surface carbon contamination of the films can be removed with anneals in argon, or incorporated in the surface with oxygen anneals. Regardless of the gas used, an insulating phase transition occurs near 300°C due to strontium segregation at the surface. The surface develops more insulating character if annealed with oxygen. Different species are proposed to be responsible for the discrepancy in insulating character