0000000000073634
AUTHOR
Eckart Rühl
When are thin films of metals metallic? Part III
Abstract A large amount of experimental information has indicated that very thin films of metallic elements can exhibit nonmetallic behavior, even on metal substrates. These films undergo a gradual nonmetal to metal transition with increasing film density or thickness. The nonmetallic behavior can be related to electron localization due to strong electron-electron correlation in low dimensional systems, as indicated by the strong enhancement of electron effective mass. The evolution in the electronic structure associated with the nonmetal to metal transition bears a striking resemblance to the behavior observed for free metal clusters. Part I [1], outlined the general concepts of a nonmetal…
Ionization Energies of ClO and Cl2O2
The ionization energies of chlorine oxide (ClO) and its dimer (Cl2O2) have been measured using monochromatic synchrotron radiation in the 10−20 eV energy regime in combination with photoionization mass spectrometry. The threshold energy of ClO+ (m/z = 51) is found at 10.85 ± 0.05 eV, whereas the ionization threshold of Cl2O2+ (m/z = 102) occurs at 11.05 ± 0.05 eV. The experimental values are compared to results from ab initio calculations, where three stable isomers of Cl2O2 are considered: dichlorine peroxide (ClOOCl), chloryl chloride (ClClO2), and chlorine chlorite (ClOClO). The results indicate that the experimental threshold energy of Cl2O2+ is due to adiabatic ionization of ClOOCl. T…
Enhancing the sensitivity of nano-FTIR spectroscopy.
Synchrotron radiation-based nano-FTIR spectroscopy utilizes the highly brilliant and ultra-broadband infrared (IR) radiation provided by electron storage rings for the infrared spectroscopic characterization of samples at the nanoscale. In order to exploit the full potential of this approach we investigated the influence of the properties of the radiation source, such as the electron bunch shape and spectral bandwidth of the emitted radiation, on near-field infrared spectra of silicon-carbide (SiC). The adapted configuration of the storage ring optics enables a modification of the transverse electron bunch profile allowing an increase of the measured near-field signal amplitude. Additionall…
Inner-shell excitation spectroscopy of closo-carboranes
Oscillator strength spectra in the region of B 1s and C 1s excitation of three isomeric carborane cage compounds [closo-1,2-orthocarborane, closo-1,7-metacarborane, closo-1,12-paracarborane (C2B10H...