Changes to the occupied and unoccupied electronic structure of TiO2(100) upon alkali metal reduction

Direct and inverse ultraviolet photoemission spectroscopy (UPS and IPS) are used to measure the occupied and unoccupied electronic structure of TiO2(100)1x1 and TiO2(100)c(2x2)K. UPS results from stoichiometric TiO2(100)1x1 are in good agreement with earlier studies. IPS data recorded from TiO2(100)1x1 show two distinct features with energy positions 1.7 eV and 5.3 eV above the Fermi level (EF). These features are associated with the Ti 3d derived t2g and eg levels. Upon formation of TiO2(100)c(2x2)K, achieved by annealing K treated TiO2(100)1x1, several changes are observed to occur to the surface electronic structure. Population of a band gap state pins EF and removes band bending at the surface. The valence band of TiO2(100)c(2x2)K is noted to be substantially narrower (of the order of 0.5 eV) than that of TiO2(100)1x1. In addition to this, a sharp feature lying to the high binding energy side of the valence band is populated. Concurrently, intensity in the Ti t2g derived conduction band level is lost. This redistribution of spectral intensity observed between TiO2(100)1x1 and TiO2(100)c(2x2)K is interpreted in terms of a K induced redistribution of charge at the surface. We use resonant photoemission to test the idea that this charge redistribution involves mainly the Ti d levels

Surface relaxation of SrTiO₃(001)

Surface X-ray diffraction has been used to examine the 300 K structure of SrTiO3(001)1×1 with a termination of 78% TiO and 22% SrO. The data indicate that a lateral ferroelectric distortion is absent on both terminations, consistent with a recent theoretical calculation. Although the negligible Ti atom relaxation found on the TiO termination is consistent with medium-energy ion scattering data, it differs from recent density functional theory calculations by 0.13 and 0.16 Å. In contrast, the Sr displacement towards the SrO surface of 0.22±0.07 Å is in good agreement with theory

Natural Abundance 14C Content of Dibutyl Phthalate (DBP) from Three Marine Algae

Abstract: Analysis of the natural abundance 14C content of dibutyl phthalate (DBP) from two edible brown algae, Undaria pinnatifida and Laminaria japonica, and a green alga, Ulva sp., revealed that the DBP was naturally produced. The natural abundance 14C content of di-(2-ethylhexyl) phthalate (DEHP) obtained from the same algae was about 50-80% of the standard sample and the 14C content of the petrochemical (industrial) products of DBP and DEHP were below the detection limit

Copper interface induced relaxation of TiO2(110)-1×1

Surface x-ray diffraction has been used to examine the effect of a Cu overlayer on the bulk structural relaxations of TiO 2 (110)1×1). The Ti atoms at this buried interface are at close to their bulk-terminated positions, representing a derelaxation from the clean surface positions by up to about 0.2 Å. In contrast, O atom vertical and lateral displacements are enhanced, with values of up to 0.4±0.1 Å and 0.6±0.1 Å, respectively. This enhanced relaxation is consistent with Cu-O bonding

CCDC 689859: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures