PHY012 Medium Energy Ion Scattering Spectrometry of Spinel Li4Ti5O12 Surface

Abstract

Applying scanning tunneling microscopy (STM) and medium energy ion scattering (MEIS) to a Li₄Ti₅O₁₂ (111) film prepared from a TiO2 wafer, we found that there exists two kinds of Li-terminated (111) terraces bounded by steps with different heights. In the major terraces, the top hexagonal Li layer is stacked above the oxygen layer, while the top Li layer is stacked above the Ti-Li layer in the minor terraces. The relative stability between the two surface structures seems to depend on the atmosphere due to different stoichiometry, which is a possible origin of CO₂ generation via redox interaction with electrolyte molecules.