Functional Oxide Discovery using Combinatorial Methods
Screening for a mixed-conductor
Mixed conductors possess both ionic and electronic conductivity. The combination of these two properties is essential for active electrode materials, however ionic conductivity is the more difficult property to measure on the solid oxides. Our approach will be to determine the oxygen diffusion coefficient and the oxygen surface exchange coefficient of our samples. This is done by exchanging oxygen 16 in the ceramic with an oxygen 18 isotope and measuring its diffusion via Secondary Ion Mass Spectrometry (SIMS). The ceramic group of Imperial College has more than 20 years of experience of performing the type of exchange-SIMS procedure, especially in the field of oxygen ion ceramic conductors.
The first part of this project was to test if the high throughput screening methods produce the same trend in diffusion coefficients as observed in materials made by the usual chemical synthesis. The experiments carried out at the beginning of the FOXD project were made on well known perovskites, LaSrMnO3 and LaSrCoO3. After validation of the accuracy of the high throughput screening, the project has moved forward onto a second step by discovering and analysing new materials such as perovskite-related materials to try and identify possible new materials for SOFC applications.
Mixed conductors possess both ionic and electronic conductivity. The combination of these two properties is essential for active electrode materials, however ionic conductivity is the more difficult property to measure on the solid oxides. Our approach will be to determine the oxygen diffusion coefficient and the oxygen surface exchange coefficient of our samples. This is done by exchanging oxygen 16 in the ceramic with an oxygen 18 isotope and measuring its diffusion via Secondary Ion Mass Spectrometry (SIMS). The ceramic group of Imperial College has more than 20 years of experience of performing the type of exchange-SIMS procedure, especially in the field of oxygen ion ceramic conductors.
The first part of this project was to test if the high throughput screening methods produce the same trend in diffusion coefficients as observed in materials made by the usual chemical synthesis. The experiments carried out at the beginning of the FOXD project were made on well known perovskites, LaSrMnO3 and LaSrCoO3. After validation of the accuracy of the high throughput screening, the project has moved forward onto a second step by discovering and analysing new materials such as perovskite-related materials to try and identify possible new materials for SOFC applications.