Measurement of SnO₂ Nanoparticles Coating on Titanium Dioxide Nanotube Arrays Using Grazing-Incidence X-Ray Diffraction

Grazing-incidence X-ray diffraction measurements (GIXRD) were performed on thin films of SnO₂ nanoparticles coating on the TiO₂-nanotube arrays using a common X-ray diffractometer with focusing light, Shimadzu XRD-7000. By GIXRD analysis, the phase components of the coating on titanium oxide nanotube arrays were disclosed, and a multi-layer structure is established: SnO₂ crystal phase, TiO crystal phase and amorphous phase with SnO₂ composition, from the top down, respectively. It is shown from the GIXRD results that, there is obvious diffraction peak broadening phenomenon corresponding to the decreasing X-ray incident angles (ω ≥ 2°) due to the crystals on the surface, which is caused by the nonparallel X-rays scattering on the sample’s surface, while for the crystal under the surface, there is no this phenomenon observed, even for crystals much closer to the surface. This provides a method for distinguishing the crystals on the surface or under the surface.