Maria Gomez of Mount Holyoke College is supported by a RUI award from the Chemical Theory, Models and Computational Methods program in the Chemistry division for research that aims to understand grain boundary structure and how it affects preferred proton conduction pathways in doped perovskite oxides. The proposal is co-funded by the Condensed Matter Materials Theory program in the Division of Materials Research. A systematic study of the ensemble of proton conduction pathways across tilt and twist grain boundaries of the most stable surfaces is being undertaken using a combination of electronic structure methods and graph theory. With these ensembles, the most probable paths and averages of the limiting barrier across a grain boundary are found. Further, by combining graphs for the grain boundary core with graphs for two differently doped bulk systems, the effect of increasing dopant concentration at the grain boundary are considered.
Understanding the impact of grain boundaries on proton conduction can help set goals for the making of efficient proton conductors. In addition to expanding our understanding of how grain boundaries affect proton conduction paths, which could impact fuel cell design, this project has a broader impact on the training of future scientists, and is being carried out entirely with undergraduate student researchers at Mount Holyoke College, the oldest continuing undergraduate liberal arts college for women in the United States. The student participants will present their undergraduate research at national or regional meetings, and co-author publications. The PI will plan an Adventure Day about energy and materials in the Passport to Chemistry Adventure program she runs for parent/child teams who complete a series of kits at their local public libraries.