Abstract: The paper reports on surface spectroscopy measurements of silicon single-crystal wafers which have been treated in order to obtain hydrophilic and hydrophobic surfaces, respectively. The wafers are characterized in terms of the oxidation behaviour in air (“native oxides”), their surface chemical composition and the chemical bonds involved. It is shown that the oxide on hydrophilic wafers mainly grows in the cleaning agent and consists of hydrated SiO2 through all stages of the growth. On a hydrophobic surface, however, the oxidation begins with the formation of a lower oxidation state which turns into SiO2 on storage in air. The thickness of the oxides on both surface types reaches 1.4–1.5 nm. Both the chemical shift in photoelectron spectroscopy and the frequency of the asymmetric Si-O-Si vibration in electron energy loss spectroscopy support the assumption of a reduced bonding angle of the oxygen bridge. Hydrophilicity is caused by singular and associated OH groups on the surface. Singular groups could be detected up to 700 K. There are hints that OH groups stabilize the oxide during heating. The hydrophobic state is mainly characterized by Si-H and Si-CH x groups on the surface, whereas Si-F exists only in minor quantities. Si-H groups were stable up to approximately 900 K in UHV. Si-CH x dehydrogenizes at temperatures between 500 and 700 K leaving SiC on the surface.

Abstract: There has long been a widespread interest in the feasibility of Fourier transform Raman spectroscopy. The well-deserved reputation of FT-IR has generated hopes for similar benefits in Raman spectroscopy, and the complementarity of IR and Raman spectroscopy has made the use of a single instrument for both spectroscopies both convenient and cost-effective.

Abstract: Introduction to NMR Spectroscopy Instrumental Methods of 13C NMR Spectroscopy 13C NMR Spectral Parameters and Structural Properties 13C NMR Spectroscopy of Organic Compounds 13C NMR Spectra of Natural Products References.

Abstract: Resolution Enhancement of Infrared Spectra of Biological Systems Peptide Backbone Conformation and Microenvironment of Protein Side Chains Raman and UV Resonance Raman Spectra of Proteins and Related Compounds Local Conformations and Polymorphism of DNA Duplexes as revealed by their Raman Spectra Applications of Raman Spectroscopy in Structural Studies of Viruses, Nucleo-proteins and their Constituents Drug-Nucleic Acid Interactions Normal Analysis of Large Molecules of Biological Interest: Metalloporphyrins and Lumiflavin Resonance Raman Spectroscopy of Flavins and Flavoproteins Resonance Raman Spectra of Reaction Intermediates of Heme Enzymes.

Abstract: We report high-resolution inverse Raman spectroscopy measurements of nitrogen Q-branch linewidths in pure nitrogen at temperatures up to 1500 K and at pressures from 20 to 760 Torr. Transitions from J = 0 to J = 30 have been measured with a resolution of 1.5 × 10−3 cm−1 and a Raman shift accuracy of 1 × 10−3 cm−1. Fits to the data using a Galatry line-shape model provide J-dependent collisional-broadening coefficients. A modified exponential-gap scaling law accurately describes the dependence of these coefficients on temperature and rotational quantum number.

Abstract: Introduction Ultraviolet (UV) Spectroscopy Infrared (IR) Spectroscopy Mass Spectrometry Nuclear Magnetic Resonance (NMR) Spectroscopy 13C NMR Spectroscopy Miscellaneous Topics Determing the Structure of Organic Molecules from Spectra Problems Appendix Index

Abstract: A detailed 21 cm study of areas of that have the smallest known amount of HI in the northern sky was performed These observations were corrected for stray radiation The region of main interest, around alpha = 10(h)45(m), delta = 57 deg 20', has a minimium N(HI) of 45 x 10 to the 19th power/sq cm Spectra taken at 21' resolution over a field 4 x 3 deg in this direction show up to four HI line components Two, near 0 and -50 km/s, are ubiquitous There is also a narrow component at -10 km/s attributable to a diffuse cloud covering half of the field, and scattered patches of HI at v -100 km/s the low and intermediate velocity components have a broad line width and are so smoothly distributed across the region that it is unlikely that they contain significant unresolved angular structure Eight other low column density directions were also observed Their spectra typically have several components, but the total column density is always 7 x 10 to the 19th power/sq cm and changes smoothly along a 2 deg strip Half of the directions show narrow lines arising from weak diffuse HI clouds that contain 05 to 30 x 10 to the 19th power/sq cm

Abstract: Hydrogen peroxide has been optically excited at a wavelength of 266 nm and the OH photofragment completely characterized by Doppler and polarization spectroscopy using the laser‐induced fluorescence technique. The entire internal state distribution (vibration, rotation, spin, and Λ components), translational energy, angular distribution, rotational alignment, and vector correlations between rotational and translation motions of OH products is measured. The hydroxyl radicals are formed in the X 2Π3/2,1/2 ground state with 90% of the available energy (248 kJ/mol) being released as OH recoil translation. The angular distribution is nearly a sin2 θ distribution about the electric vector of the photolysis laser. The internal motion of OH is vibrationally cold (no vibrationally excited OH was found) while the rotational excitation in v‘=0 can be described by a Boltzmann distribution with a temperature parameter of Trot=(1530±150) K. The two spin states are found to be populated nearly statistically, in contrast...

Abstract: Great advances have been made in the past decade in the field of NMR spectroscopy. Apart from the development of completely new areas of application, such as in solid-state chemistry, in materials science, in physiological chemistry, and in medicine, with the introduction of new pulse spectroscopic methods and the application of high magnetic field strengths important progress has also been made in the traditional field of high-resolution NMR spectroscopy. Thus, among other things, the observation of metal resonances has been facilitated and new areas of application have been opened up in inorganic and organometallic chemistry. In this review, recent detection methods for spin-1/2 and quadrupolar metal nuclei are presented and discussed. The use of metal-NMR spectroscopy with respect to problems of a typical chemical nature, mainly from the field of organometallics, is demonstrated for a number of selected metal nuclei (25Mg, 27Al, 49Ti, 57Fe, 59Co, 61Ni, 91Zr, 103Rh, and 195Pt). Relations found empirically between chemical shifts and coordination number, oxidation number, and electronic configuration of a metal bound in a complex are emphasized. Furthermore, cases in which the chemical shifts of metal nuclei can be interpreted in terms of the energy difference of frontier orbitals are presented. This aspect leads to the establishment of a relationship between chemical reactivity and NMR parameters for a series of related compounds.

Abstract: A high resolution soft X-ray monochromator for the 550 MeV MAX storage ring is described. The instrument combines a plane elliptical premirror collecting a large (10 mrad) horizontal angle of radiation and a modified version of the well-known SX-700 plane grating monochromator (PGM). The modification consists of changing the original ellipsoidal focussing mirror to a plane elliptical mirror. Thereby the horizontal and vertical focussing are decoupled and good imaging properties are obtained irrespective of the large horizontal acceptance angle. The MAX-PGM will be part of an experimental station for photoelectron, photoabsorption and photon stimulated ion desorption spectroscopy.

Abstract: X‐ray photoelectron spectroscopy and ion scattering spectroscopy studies of HF‐treated silicon surfaces are described in an effort to understand the chemical termination leading to the near ideal electrical passivation of such surfaces. Results suggest a fluorine surface density of order a monolayer chemically bonded to silicon with a partial oxygen contamination due to exposure of the HF‐treated wafer to air, and a physisorbed hydrocarbon layer on top.

Abstract: The use of vibrational spectroscopy to probe the structure and dynamics of biological molecules is a rapidly expanding area of research. Its origins, however, lie in the early studies of simple, organic molecules by infrared and Raman techniques. The comparison of vibrational spectra with molecular structure provided organic chemists with correlation charts which are the basis of sample analysis today. A standard text describing this approach is that of Bellamy (1975). Analysis of biological molecules is a more recent development and excellent reviews are those of Susi (1969), Fraser and MacRae (1973), Fawcett and Long (1973), and Thomas and Kyogoku (1977). The application of infrared and Raman techniques in membrane research has been reviewed by Wallach et al. (1979), Fringeli and Gunthard (1981), Amey and Chapman (1983), Levin (1984), and Casal and Mantsch (1984). The amount of structural and functional information available to the IR spectroscopist who is interested in biological systems is expanding rapidly with the application of increasingly sophisticated methods for data acquisition and analysis and new techniques in sample handling. These techniques include the detection and assignment of minor spectral components using derivative and deconvolution calculations, the study of biochemical reactions using kinetic IR spectroscopy and the use of cylindrical internal reflection cells for easy analysis of aqueous samples. Initially, the major problem in the study of biological molecules was the absorption of liquid water over much of the IR spectrum. This severely limited the analysis of samples in their natural state and necessitated the use of high concentrations, low pathlength cells (less than 50 gm) or deuterium oxide as a solvent. The advent of microprocessor-controlled spectroscopy has permitted the subtraction

Abstract: A new method for performing high-frequency, visible FM spectroscopy by using low-frequency detection is demonstrated. By using this technique, a detection limit of 323 μTorr m (path length) has been established for atmospheric-pressure-broadened NO2. This corresponds to a differential absorption of 1.0 × 10−5.

Abstract: ,

Abstract: The dependence of technically important properties of wear resistant nitride coatings on chemical composition requires advanced methods of compositional analysis to establish optimized fabrication processes. High spatial resolution and chemical bonding specificity are provided by such techniques as Auger electron spectroscopy (AES) in the form of scanning Auger microscopy (SAM) and x‐ray photoelectron spectroscopy (XPS). A survey is given for the study of reactively sputter deposited Ti–N, Hf–N, and Ti–Al–N coatings on high‐speed steel substrates using point, line, and in‐depth distribution analysis by SAM in conjunction with sputter profiling. Capabilities and limitations of quantitative AES to determine the influence of processing parameters on coating composition are presented. XPS gives additional information on chemical bonding and on quantification. This is particularly important in cases of peak overlapping in Auger spectra (e.g., TiN).

Abstract: A B S T RA C T: The mechanism of Ni-Mg substitution has been studied by X-ray absorption spectroscopy in phyllosilicates belonging mainly to the lizardite--nepouite and kerolite-pimelite series. Two types of information were obtained: (1) Analysis of nickel K-edge spectra under high resolution confirmed that Ni atoms were substituted for Mg atoms. There was no evidence for 4-fold coordinated Ni. (2) Extended X-ray absorption fine structure (EXAFS) was sensitive to atomic pair-correlations and gave access to the radial distribution function around Ni atoms. For all samples, this function gave two peaks. The first one was related to the (O,OH) coordination shell and analysis confirmed that Ni atoms were 6-fold coordinated. The amplitude of the second peak was very sensitive to the atomic composition of the Ni-Mg second shell. It is shown that the intracrystalline distribution of Ni is never random within the octahedral sheet; Ni atoms are segregated into domains, the minimum size of which has been calculated. In the kerolite--pimelite series the mean domain size is at least 30 ./~ and EXAFS could not exclude the existence of pure Ni sheets. X-ray dispersive spectroscopy combined with TEM suggested that the minerals in this series have pure Ni layers associated with pure Mg layers. In the lizardite-nepouite series, Ni atoms are segregated into specific Ni-enriched areas, the exent of which depends on the specific chemical constitution of the sample. Distribution patterns are discussed with respect to the formation mechanisms of these ore minerals.

Abstract: The photofragmentation dynamics of H2O molecules following vacuum ultraviolet laser excitation at wavelengths within the B1A1–X1A1 absorption band have been investigated using a novel from of photofragment translational spectroscopy Analysis of the nascent H atom time-of-flight spectra confirms the importance of the dissociation channel leading to ground-state H + OH products In addition, it reveals that the OH(X) fragments are formed predominantly in their zero-point vibrational level with a highly excited, inverted rotational-state population distribution A consideration of the topology of the various potential-energy surfaces sampled by the H2O molecules during this electronically non-adiabatic dissociation process suggests a likely explanation for this observed pattern of energy disposal

Abstract: Solute–solvent clusters of pyrazine, pyrimidine, and benzene (solutes) and CnH2n+2 (n=1,2), NH3, and H2O (solvents) are studied by the techniques of supersonic molecular jet spectroscopy and two‐color time‐of‐flight mass spectroscopy (two‐color TOFMS) Spectral shifts, van der Waals (vdW) modes, dissociation energies, and vdW mode–solute mode vibronic couplings are characterized for most of the observed clusters Based on these data and previous results for hydrocarbon systems, cluster geometries can be suggested Lennard‐Jones potential (6‐12‐1) calculations are also performed for these clusters and in all instances for which comparisons can be readily made, calculated and experimentally estimated geometries and binding energies agree completely Clusters of N‐heterocyclic solutes and H2O are not observed experimentally Systematics and trends among the clusters reported herein and those previously reported are discussed and analyzed

Abstract: Synchrotron radiation from the German storage ring BESSY has been used to study the photoelectron spectrum of the water molecule. Asymmetry parameters and relative photoionization cross sections have been measured for all four molecular orbitals (2a1, 1b2, 3a1, and 1b1) in the 30–140 eV photon energy range. The results have been compared with the Xα calculations of Roche, Salahub, and Messmer and good agreement was found. Comparison was also made with a number of previous measurements, including those obtained by (e,2e) spectroscopy. Finally, the inner valence (2a1) region has been studied at 60 and 100 eV photon energies and the relative intensities of some of the satellites were found to change as the exciting energy was varied.

Abstract: A surface-potential stabilization technique is described which permits one to take vibrational spectra of excellent quality with high-resolution electron-energy-loss spectroscopy on insulating samples of very different types, such as ionic insulators and polymers. Induced surface conductivity and enhanced secondary-electron emission close to the vacuum level are found to be at the origin of the surface-potential stabilization, which is done by irradiation of the sample with electrons in the keV range. Nonequilibrium carrier densities and mean free paths are estimated from observable Drude damping. Irradiation effects are discussed.