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We demonstrate how the orientation and ordering of DNA bases in ultrahigh vacuum (UHV) and ambient environments can be determined using complementary spectroscopic methods. Near-edge X-ray absorption fine structure (NEXAFS) with fluorescence detection, X-ray photoelectron (XPS), and Fourier transform infrared (FTIR) spectroscopies are used to quantify the(More)
It has been proposed that the Si(557)-Au surface exhibits spin-charge separation in a one-dimensional electron liquid. Two narrowly spaced bands are found which exhibit a well-defined splitting at the Fermi level. That is incompatible with the assignment to a spinon-holon pair in a Luttinger liquid. Instead, we propose that the two bands are associated with(More)
It has been a long-standing goal to create magnetism in a non-magnetic material by manipulating its structure at the nanoscale. Many structural defects have unpaired spins; an ordered arrangement of these can create a magnetically ordered state. In this article we predict theoretically that stepped silicon surfaces stabilized by adsorbed gold achieve this(More)
It is shown that electron-phonon interaction provides a natural explanation for the unusual band dispersion of the metallic surface states at the Si(111)-(7 x 7) surface. Angle-resolved photoemission reveals a discontinuity of the adatom band at a binding energy close to the dominant surface phonon mode at h(omega0) = 70 meV. This mode has been assigned to(More)
DESCRIPTION. The Journal of Physics and Chemistry of Solids is a well established international medium for publication of research in condensed matter and materials science. Emphasis is placed on experimental and theoretical work which contributes to a basic understanding of and new insight into the properties and behavior of condensed matter. General areas(More)
Polarization-dependent near edge X-ray absorption fine structure (NEXAFS) spectroscopy was used to determine the ordering of octadecyltrichlorosilane (OTS) molecules in self-assembled (SA) films on Si/SiOx. Coverages of adsorbed material for different SA films were determined by integration of the NEXAFS signal due entirely to the C 1s absorption. The(More)
We report for the first time the chemical synthesis of free-standing single-crystal nanowires (NWs) of FeSi, the only transition-metal Kondo insulator and the host structure for ferromagnetic semiconductor Fe(x)Co(1-x)Si. Straight and smooth FeSi nanowires are produced on silicon substrates covered with a thin layer of silicon oxide through the(More)
The influence of in-plane biaxial strain on the conduction bands of Si is explored using elastically strained Si(001) nanomembranes and high-resolution x-ray absorption measurements with electron yield detection. The strain-induced splitting of the conduction band minimum and the energy shifts of two higher conduction bands near L1 and L3 are clearly(More)
Copper and zinc phthalocyanines and porphyrins are used in organic light emitting diodes and dye-sensitized solar cells. Using near edge x-ray absorption fine structure (NEXAFS) spectroscopy at the Cu 2p and Zn 2p edges, the unoccupied valence states at the Cu and Zn atoms are probed and decomposed into 3d and 4s contributions with the help of density(More)
We report direct measurements of changes in the conduction-band structure of ultrathin silicon nanomembranes with quantum confinement. Confinement lifts the 6-fold-degeneracy of the bulk-silicon conduction-band minimum (CBM), Delta, and two inequivalent sub-band ladders, Delta(2) and Delta(4), form. We show that even very small surface roughness smears the(More)