A Comparative Study on Crystallization Behavior, Phase Stability, and Binding Energy in Pure and Cr-Doped TiO2 Nanotubes

This chapter describes the effect of Cr doping by ion implantation on the in situ crystallization and phase stability of anodic TiO₂ nanotubes at elevated temperature. It presents X-ray diffraction (XRD) results of the role of Cr doping on the in situ crystallization behavior and phase stability of TiO₂ nanotubes in the temperature range of 25–1000°C. The effects of Cr doping on the resultant microstructure, composition depth profile, and binding energy are discussed in terms of scanning electron microscopy, ion-beam analysis by Rutherford backscattering spectrometry, and XPS. Ion-beam analysis by Rutherford backscattering spectrometry has confirmed the existence of Cr ions composition gradation in doped TiO₂. The real doping of Ti lattices with Cr ions was evidenced by the analyses of surface compositions and chemical states of the nanotubes using X-ray photoelectron spectroscopy.