The thermal stability of acetaldehyde on Si(111)7×7 was studied with HREELS, XPS, UPS, and TPD techniques. Acetaldehyde molecules were found to adsorb molecularly on the surface at 120 K, yielding HREELS peaks at 98, 124, 144, 185, and 380 and UPS peaks at 5.7, 7.6, 10.0, and 13.9 eV below Ef. Analysis of the XPS O1s (shoulder at 531; 532 eV) and C1s (288 and 285 eV) spectra indicated that the ...

O Kand Zn and Au L3-edge x-ray absorption near-edge structure XANES , x-ray emission spectroscopy XES , and scanning photoelectron microscopy SPEM are performed to investigate the electronic structure of ZnO nanorods with nanocrystalline nc -Au particles grown on the surfaces. The XANES spectra of nc-Au/ZnO nanorods reveal the decrease of the number of both O 2p and Zn 4s /3d unoccupied states ...

The effect of laser irradiation using three different wavelengths (IR, visible and UV) generated from Nd:YAG laser on the local glass structure as well as on the valence state of the copper ions in copper phosphate glass containing CuO with the nominal composition 0.30(CuO)–(0.70)(P2O5), has been investigated by X-ray photoelectron spectroscopy (XPS). The presence of asymmetry and satellite pea...

Auger and X-ray photoelectron spectroscopies have been used to study the surface composition of MnxCo1−xO (0 ≤ x ≤ 1) solid solutions. The polycrystalline materials, which are bulk homogeneous, present clear signs of deviation in surface composition at xbulk ≈ 0.2–0.4 to become surface-enriched in manganese at the expense of the cobalt. Whether on stoichiometric or cobalt-depleted surfaces, cob...

A full set of calculations is presented for inner-shell n = 2 to 3 photoexcitation of the 16 iron charge states: Fe (Fe I) through Fe (Fe XVI). The blend of the numerous absorption lines arising from these excitations (mainly 2p 3d) forms an unresolved transition array (UTA), which has been recently identified as a prominent feature between 16 17 Å in the soft X-ray spectra of active galactic n...

Oligosilanes with attached silatranyl units were obtained by reactions of potassium oligosilanides with a silatranyl triflate. Interaction between Si and N atoms was observed in the 29Si NMR spectra (upfield-shifted SiO3 resonances) and in the solid-state structures (Si-N distances between 2.29 and 2.16 Å). The Si-N interaction can be "switched off" either by protonation of the nitrogen lone pa...

The moment analysis method (MA) has been tested for the case of 2S --> 2P ([core]ns1 --> [core]np1) transitions of alkali metal atoms (M) doped into cryogenic rare gas (Rg) matrices using theoretically validated simulations. Theoretical/computational M/Rg system models are constructed with precisely defined parameters that closely mimic known M/Rg systems. Monte Carlo (MC) techniques are then e...

Direct-gap gain up to 850 cm(-1) at 0.74 eV is measured and modeled in optically pumped Ge-on-Si layers for photoexcited carrier densities of 2.0 × 10(20) cm(-3). The gain spectra are correlated to carrier density via plasma-frequency determinations from reflection spectra. Despite significant gain, optical amplification cannot take place, because the carriers also generate pump-induced absorpt...

We have observed visible photoluminescence (PL) spectra (peak energy: 3.1 eV) of size-controlled silicon (Si) nanoparticles annealed in oxygen gas. The PL peak energy did not depend on the temperature, and the PL lifetime was relatively fast (on the order of nanoseconds). It was inferred that the visible PL was attributed to localized states in the oxidized surfaces of size-controlled Si nanopa...