Investigation of anodic TiO2 nanotube composition with high spatial resolution AES and ToF SIMS

Abstract High resolution Scanning Auger Electron Spectroscopy (AES) and Time-of-Flight Secondary Ion Mass-Spectrometry (ToF SIMS) were used to investigate structure and elemental composition variation of both across an array of TiO 2 nanotubes (NTs) and single tube of an array. The TiO 2 NT array was grown by anodic oxidation of Ti foil in fluorine-containing ethylene glycol electrolyte. It was found that the studied anodic TiO 2 nanotubes have a layered structure with rather sharp interfaces. The differences in AES depth profiling results of a single tube with the focused primary electron beam (point analysis) and over an area of 75 μm in diameter of a nanotube array with the defocused primary electron beam are discussed. Depth profiling by ToF SIMS was carried out over approximately the same size of a nanotube array to determine possible ionic fragments in the structure. The analysis results show that the combination of both mentioned methods is useful for a detailed analysis of nanostructures with complex morphology and multi-layered nature.