Angle-dependent x-ray absorption near-edge structure (XANES) and scanning photoelectron microscopy measurements were performed to differentiate local electronic structures at the tips and sidewalls of highly aligned ZnO nanorods. The overall intensity of the O K-edge XANES spectra is greatly enhanced for small photon incident angles. In contrast, the overall intensity of the Zn K-edge XANES is much less sensitive to the photon incident angle. Both valence-band photoemission and O K-edge XANES spectra show substantial enhancement of O 2p derived states near the valence band maximum and conduction band minimum, respectively. The spatially resolved Zn 3d core level spectra from tip and sidewall regions show the lack of chemical shift. All the results consistently suggest that the tip surfaces of the highly aligned ZnO nanorods are terminated by O ions and the nanorods are oriented in the [0001̄] direction.

O K -, ZnL3, and K-edges x-ray absorption near-edge structure (XANES) spectra and scanning photoelectron microscopy (SPEM) spectra were obtained for ZnO nanorods with various diameters. The analysis of the XANES spectra revealed increased numbers of O2p and Zn4p unoccupied states with the downsizing of the nanorods, which reflects the enhancement of surface states when the diameter is decreased. Valence-band photoemission spectra show a significant narrowing of the valence band for the 45nm diameter nanorod. The Zn3d intensities in the Zn3d SPEM spectra are drastically diminished for all nanorods as compared to the ZnO reference film, which can be interpreted as a reduction in density of itinerant final states or in transition probability.

This work presents the O K-and Ti L 3,2-edge x-ray absorption near-edge structure ͑XANES͒ spectra of Pb x Sr 1−x TiO 3 ͑P x STO͒ and Ba x Sr 1−x TiO 3 ͑B x STO͒ compounds with various Pb and Ba concentrations. The result provides direct evidence that the Pb-O bonding strongly affects O 2p-Ti 3d hybridization in the TiO 6 octahedron of P x STO. In contrast, the Ba-O bonding does not substantially affect O 2p-Ti 3d hybridization in B x STO. The Ti L 3-edge XANES spectra show the splitting of the e g band for P x STO with x տ 0.5, which provides an evidence of Pb-induced tetragonal distortion in the TiO 6 octahedron. In contrast, e g band splitting is absent in B x STO.

This study performs O K-and Ti L 3,2-edge x-ray absorption near-edge structure ͑XANES͒ measurements and first-principles pseudopotential calculations for the electronic structures of ABO 3-type Pb 1Ϫx Ca x TiO 3 (xϭ0-1) perovskites. The features in the O K-edge XANES spectra are found to be contributed primarily by hybridization between O 2p and Ti 3d, Pb 6p, and Ca 3d orbitals. The O K-edge XANES spectra reveal that partial substitution of A cations, Pb, by Ca not only decreases O 2p-Pb 6p but also O 2p-Ti 3d hybridization. The Ti L 3,2-edge measurements find that the off-center displacement of Ti, and hence, ferroelectricity persist up to a Ca concentration between 0.3 and 0.4.

X-ray-absorption near edge structure ͑XANES͒ measurements have been performed to investigate the local electronic structures of the Fe-catalyzed and stabilized carbon nanotubes ͑CNT͒ with various diameters. The intensities of the *and *-band and the interlayer-state features in the C K-edge XANES spectra of these CNTs vary with the diameter of the CNT. The white-line features at the C K-and Fe L 3 -edges suggest a strong hybridization between the C 2p and Fe 3d orbitals, which lead to an enhancement of the C K-and reduction of the Fe L 3 -edge features, respectively, indicative of a charge transfer from C 2p to Fe 3d orbitals. The Fe K-edge spectra reveal a p -d rehybridization effect that reduces p-orbital occupation at the Fe site.