Electron Probe for Unequivocal Surface Characterization and Surface Defect Engineering of Energy Materials. Example of BaTiO.

Surface properties of crystalline solids and the related defect disorder of the surface layer have a critical effect on the reactivity and performance of materials, including energy materials. It is shown here that a high-temperature electron probe enables unequivocal surface characterization of energy oxide materials in a gas/solid equilibrium, including the affinity-related charge transfer and segregation-affected defect disorder. As an example, this work considers surface monitoring of barium titanate at elevated temperatures during oxidation to determine a quantity (described as work function) that is reflective of the chemical potential of electrons during gas/solid reactions. The probe enables insight into local surface structures and opens up new fields of surface defect chemistry and surface defect engineering of materials for clean energy conversion.