Abstract: Here we report the synthesis, structure, and optical properties of ca. 100 nm star-shaped gold nanoparticles. Single particle spectroscopy measurements revealed that these nanoparticles have multiple plasmon resonances resulting in polarization-dependent scattering with multiple spectral peaks, which correspond to the different tips on the star-shaped structure. The plasmon resonances were also found to be extremely sensitive to the local dielectric environment.

Abstract: The surface properties of PtM (M = Co, Ni, Fe) polycrystalline alloys are studied by utilizing Auger electron spectroscopy, low energy ion scattering spectroscopy, and ultraviolet photoemission spectroscopy. For each alloy initial surface characterization was done in an ultrahigh vacuum (UHV) system, and depending on preparation procedure it was possible to form surfaces with two different compositions. Due to surface segregation thermodynamics, annealed alloy surfaces form the outermost Pt-skin surface layer, which consists only platinum atoms, while the sputtered surfaces have the bulk ratio of alloying components. The measured valence band density of state spectra clearly shows the differences in electronic structures between Pt-skin and sputtered surfaces. Well-defined surfaces were hereafter transferred out from UHV and exposed to the acidic (electro)chemical environment. The electrochemical and post-electrochemical UHV surface characterizations revealed that Pt-skin surfaces are stable during and af...

Abstract: The presence of large amounts of nondiamond carbon in detonation-synthesized nanodiamond (ND) severely limits applications of this exciting nanomaterial. We report on a simple and environmentally friendly route involving oxidation in air to selectively remove sp2-bonded carbon from ND. Thermogravimetric analysis and in situ Raman spectroscopy shows that sp2 and sp3 carbon species oxidize with different rates at 375−450 °C and reveals a narrow temperature range of 400−430 °C in which the oxidation of sp2-bonded carbon occurs with no or minimal loss of diamond. X-ray absorption near-edge structure spectroscopy detects an increase of up to 2 orders of magnitude in the sp3/sp2 ratio after oxidation. The content of up to 96% of sp3-bonded carbon in the oxidized samples is comparable to that found in microcrystalline diamond and is unprecedented for ND powders. Transmission electron microscopy and Fourier transform infrared spectroscopy studies show high purity 5-nm ND particles covered by oxygen-containing sur...

Abstract: We used a scanning tunneling microscope to probe the interactions between spins in individual atomic-scale magnetic structures. Linear chains of 1 to 10 manganese atoms were assembled one atom at a time on a thin insulating layer, and the spin excitation spectra of these structures were measured with inelastic electron tunneling spectroscopy. We observed excitations of the coupled atomic spins that can change both the total spin and its orientation. Comparison with a model spin-interaction Hamiltonian yielded the collective spin configuration and the strength of the coupling between the atomic spins.

Abstract: Surface-Enhanced Raman Spectroscopy: a Brief Perspective.- Electromagnetic Mechanism of SERS.- Electromagnetic Theory of SERS.- Coupled Plasmonic Plasmon/Photonic Resonance Effects in SERS.- Estimating SERS Properties of Silver-Particle Aggregates through Generalized Mie Theory.- Studying SERS from Metal Nanoparticles and Nanoparticles Aggregates with Continuum Models.- SERS From Transition Metals and Excited by Ultraviolet Light.- Electronic Mechanisms of SERS.- Two-Photon Excited Surface-Enhanced Raman Scattering.- Applications of the Enhancement of Resonance Raman Scattering and Fluorescence by Strongly Coupled Metallic Nanostructures.- Tip-Enhanced Raman Spectroscopy (TERS).- Tip-Enhanced Near-Field Raman Scattering: Fundamentals and New Aspects for Molecular Nanoanalysis/Identification.- Single-Molecule SERS Spectroscopy.- Temporal Fluctuations in Single-Molecule SERS Spectra.- Single-Molecule Surface-Enhanced Resonance Raman Spectroscopy of the Enhanced Green Fluorescent Protein EGFP.- Surface-Enhanced Vibrational Spectroelectrochemistry: Electric-Field Effects on Redox and Redox-Coupled Processes of Heme Proteins.- Nanosensors Based on SERS for Applications in Living Cells.- Biomolecule Sensing with Adaptive Plasmonic Nanostructures.- Glucose Sensing with Surface-Enhanced Raman Spectroscopy.- Quantitative Surface-Enhanced Resonance Raman Spectroscopy for Analysis.- Rapid Analysis of Microbiological Systems Using SERS.- Surface-Enhanced Raman Scattering for Biomedical Diagnostics and Molecular Imaging.- Ultrasensitive Immunoassays Based on Surface-Enhanced Raman Scattering by Immunogold Labels.- Detecting Chemical Agents and Their Hydrolysis Products in Water.

Abstract: Far infrared transmission experiments are performed on ultrathin epitaxial graphite samples in a magnetic field. The observed cyclotron resonancelike and electron-positron-like transitions are in excellent agreement with the expectations of a single-particle model of Dirac fermions in graphene, with an effective velocity of $\stackrel{\texttildelow{}}{c}=1.03\ifmmode\times\else\texttimes\fi{}{10}^{6}\text{ }\text{ }\mathrm{m}/\mathrm{s}$.

Abstract: Fe 3+ -doped anatase nanosized TiO 2 photocatalysts have been prepared by combining sol–gel method with hydrothermal treatment. The samples were characterized by UV–vis diffuse reflectance spectroscopy, X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET)-specific surface area ( S BET ), transmission electron microscopy (TEM), atomic absorption flame emission spectroscopy (AAS), electron paramagnetic resonance (EPR) spectroscopy and X-ray photoelectron spectroscopy (XPS). From results of UV–vis diffuse reflectance spectroscopy, Fe 3+ -doped TiO 2 extends its absorption to longer than 500 nm, which leads to an obvious photocatalatic activity under visible irradiation. From XRD, EPR, AAS and XPS, it was found that Fe exist in trivalent ionic state substituting Ti 4+ in TiO 2 lattice and its concentration decreases from the surface to the center of doped TiO 2 . The photocatalytic activity of prepared samples was investigated for the photocatalytic degradation of active yellow XRG dye. The photocatalytic activity of TiO 2 doped with appropriate content of Fe 3+ exceeded those of non-doped TiO 2 and P25 both under UV and visible light irradiation.

Abstract: Cr3+-doped anatase titanium dioxide photocatalysts were prepared by the combination of sol–gel process with hydrothermal treatment. The samples were characterized by UV–vis diffuse reflectance spectroscopy, X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) specific surface area (SBET), transmission electron microscopy (TEM), atomic absorption flame emission spectroscopy (AAS), electron paramagnetic resonance (EPR) spectroscopy and X-ray photoelectron spectroscopy (XPS). It was confirmed that Cr substitutes Ti4+ in TiO2 lattice in trivalent ionic state, and the concentrations of dopants Cr3+ decrease from the exterior to the interior of doped TiO2. The photocatalytic activity of Cr-TiO2 was investigated for the photocatalytic degradation of XRG aqueous solution both under UV and visible light irradiation. Due to the excitation of 3d electron of Cr3+ to the conduction band of TiO2, Cr-TiO2 shows a good ability for absorbing the visible light to degrade XRG. Doping of chromium ions effectively improves the photocatalytic activity under both UV light irradiation and visible light irradiation with an optimal doping concentration of 0.15% and 0.2%, respectively. The special distribution of dopants Cr3+ seems having a good effect on enhancing the photocatalytic activity of Cr-TiO2.

Abstract: [1] Gamma ray spectroscopy data acquired by Lunar Prospector are used to determine global maps of the elemental composition of the lunar surface. Maps of the abundance of major oxides, MgO, Al2O3, SiO2, CaO, TiO2, and FeO, and trace incompatible elements, K and Th, are presented along with their geochemical interpretation. Linear spectral mixing is used to model the observed gamma ray spectrum for each map pixel. The spectral shape for each elemental constituent is determined by a Monte Carlo radiation transport calculation. Linearization of the mixing model is accomplished by scaling the spectral shapes with lunar surface parameters determined by neutron spectroscopy, including the number density of neutrons slowing down within the surface and the effective atomic mass of the surface materials. The association of the highlands with the feldspathic lunar meteorites is used to calibrate the mixing model and to determine backgrounds. A linear least squares approach is used to unmix measured spectra to determine the composition of each map pixel. The present analysis uses new gamma ray production cross sections for neutron interactions, resulting in improved accuracy compared to results previously submitted to the Planetary Data System. Systematic variations in lunar composition determined by the spectral unmixing analysis are compared with the lunar soil sample and meteorite collections. Significant results include improved accuracy for the abundance of Th and K in the highlands; identification of large regions, including western Procellarum, that are not well represented by the sample collection; and the association of relatively high concentrations of Mg with KREEP-rich regions on the lunar nearside, which may have implications for the concept of an early magma ocean.

Abstract: Formation of electron pairs is essential to superconductivity. For conventional superconductors, tunnelling spectroscopy has established that pairing is mediated by bosonic modes (phonons); a peak in the second derivative of tunnel current d2I/dV2 corresponds to each phonon mode1,2,3. For high-transition-temperature (high-Tc) superconductivity, however, no boson mediating electron pairing has been identified. One explanation could be that electron pair formation4 and related electron–boson interactions are heterogeneous at the atomic scale and therefore challenging to characterize. However, with the latest advances in d2I/dV2 spectroscopy using scanning tunnelling microscopy, it has become possible to study bosonic modes directly at the atomic scale5. Here we report d2I/dV2 imaging6,7,8 studies of the high-Tc superconductor Bi2Sr2CaCu2O8+δ. We find intense disorder of electron–boson interaction energies at the nanometre scale, along with the expected modulations in d2I/dV2 (refs 9, 10). Changing the density of holes has minimal effects on both the average mode energies and the modulations, indicating that the bosonic modes are unrelated to electronic or magnetic structure. Instead, the modes appear to be local lattice vibrations, as substitution of 18O for 16O throughout the material reduces the average mode energy by approximately 6 per cent—the expected effect of this isotope substitution on lattice vibration frequencies5. Significantly, the mode energies are always spatially anticorrelated with the superconducting pairing-gap energies, suggesting an interplay between these lattice vibration modes and the superconductivity.

Abstract: We develop a method of spectroscopy that uses a weak static magnetic field to enable direct optical excitation of forbidden electric-dipole transitions that are otherwise prohibitively weak. The power of this scheme is demonstrated using the important application of optical atomic clocks based on neutral atoms confined to an optical lattice. The simple experimental implementation of this method—a single clock laser combined with a dc magnetic field—relaxes stringent requirements in current lattice-based clocks (e.g., magnetic field shielding and light polarization), and could therefore expedite the realization of the extraordinary performance level predicted for these clocks. We estimate that a clock using alkaline-earthlike atoms such as Yb could achieve a fractional frequency uncertainty of well below 10 � 17 for the metrologically preferred even isotopes.

Abstract: We present a 5m long spectrometer for soft x rays to be used at a synchrotron radiation beamline for resonant x-ray emission spectroscopy and resonant inelastic x-ray scattering in the 400–1600eV energy range. It is based on a variable line spacing spherical grating (average groove density of 3200mm−1, R=58.55m) and a charge coupled device two dimensional detector. With an x-ray spot on the sample of 10μm, the targeted resolving power is higher than 10 000 at all energies below 1100eV and better than 7000 at 1500eV. The off-line tests made with Al and MgKα1,2 fluorescence emissions indicate that the spectrometer can actually work at 12 000 and 17 000 resolving power at the L3 edges of Cu (930eV) and of Ti (470eV), respectively. SAXES (superadvanced x-ray emission spectrometer) is mounted on a rotating platform allowing to vary the scattering angle from 25° to 130°. The spectrometer will be operational at the ADRESS (advanced resonant spectroscopies) beamline of the Swiss Light Source from 2007.

Abstract: The sections in this article are Introduction Electromagnetic Mechanism of Surface-Enhanced Raman Spectroscopy for Isolated Metal Particles A simple Model: Quasistatic Treatment of an Isolated Sphere Electrostatics of Isolated Spheroids Improvements to the Spheroid Model Electrodynamic Corrections Size-Dependent Dielectric Constants Current Status of Theory/Experiment Comparisons Extensions of the Electromagnetic Model Effect of Adsorbed Layers on Intensities Nonlinear Surface Optical Processes Electromagnetic Mechanism for Many Coupled Particles and for Gratings Conclusions and Further Work Acknowledgments

Abstract: We present a proton-selective method to determine 17O-1H distances in organic, biological, and biomimetic materials by fast magic-angle-spinning solid-state NMR spectroscopy. This method allows the determination of internuclear distances between specific (17O, 1H) spin pairs selectively. It enables the estimation of medium-range 17O...1H distances across hydrogen bonds in the presence of short-range 17O-1H contacts sharing the same 17O site. The method employs the newly developed symmetry-based radiofrequency pulse sequence SR%@mt;sys@%4%@sx@%1%@be@%2%@sxx@%%@mx@% applied to the protons to achieve heteronuclear dipolar recoupling, while simultaneously decoupling the homonuclear proton dipolar interactions. Fast MAS (50 kHz) and high static magnetic fields (18.8 T) achieve the required proton spectral resolution.

Abstract: Abstract The beautiful colours of many inorganic compounds, including minerals and gemstones, as well as the mysterious cold light of luminescence emitted by these materials, have attracted the inquisitiveness of natural philosophers for centuries. The scientific study of such phenomena - the optical spectroscopy of solids - has paid rich dividends in technological advances such as lasers and other optronic devices. This is a book on the art of optical spectroscopy of solids, establishing a theoretical and experimental framework for the subject, which is well illustrated with relevant spectra and experimental data. Chapters 1 to 5 set down the quantum description of atoms, ions and defects in solids, and the interaction of such centres with electromagnetic radiation. Considerations of symmetry and the effects of lattice vibrations on the spectroscopic properties are treated in detail . The physical bases of prominent experimental techniques are presented in Chapter 6 and their application to colour centres, dopant rare-earth and transition-metal ions are described in Chapters 7 -9. The spectroscopic behaviours of magnetic ions at high concentration are detailed in Chapter 10, followed by a brief review of the operational features of solid state lasers that rely on the foregoing discussion of their optical characteristics. Finally, Chapter 12 describes the application of magneto-optical double resonance techniques to the elucidation of the optical properties of insulating and semi-conducting materials. The authors emphasize that their own interests have guided the selection of topics from the panoply of available choices. They have written the book with senior undergraduates and postgraduates in mind: it is expected also to be useful to seasoned investigators from solid state physics and engineering from inorganic chemistry, and from materials and geological sciences.

Abstract: Here we report a detailed study on spectroscopy, structure, and orientational distribution, as well as orientational motion, of water molecules at the air/water interface, investigated with sum frequency generation vibrational spectroscopy (SFG-VS). Quantitative polarization and experimental configuration analyses of the SFG data in different polarizations with four sets of experimental configurations can shed new light on our present understanding of the air/water interface. Firstly, we concluded that the orientational motion of the interfacial water molecules can only be in a limited angular range, instead of rapidly varying over a broad angular range in the vibrational relaxation time as suggested previously. Secondly, because different vibrational modes of different molecular species at the interface has different symmetry properties, polarization and symmetry analyses of the SFG-VS spectral features can help the assignment of the SFG-VS spectra peaks to different interfacial species. These analyses concluded that the narrow 3693 cm(-1) and broad 3550 cm(-1) peaks belong to C(infinityv) symmetry, while the broad 3250 and 3450 cm(-1) peaks belong to the symmetric stretching modes with C2v symmetry. Thus, the 3693 cm(-1) peak is assigned to the free OH, the 3550 cm(-1) peak is assigned to the singly hydrogen-bonded OH stretching mode, and the 3250 and 3450 cm(-1) peaks are assigned to interfacial water molecules as two hydrogen donors for hydrogen bonding (with C2v symmetry), respectively. Thirdly, analysis of the SFG-VS spectra concluded that the singly hydrogen-bonded water molecules at the air/water interface have their dipole vector directed almost parallel to the interface and is with a very narrow orientational distribution. The doubly hydrogen-bonded donor water molecules have their dipole vector pointing away from the liquid phase.

Abstract: We simultaneously determined the physical structure and optical transition energies of individual single-walled carbon nanotubes by combining electron diffraction with Rayleigh scattering spectroscopy These results test fundamental features of the excited electronic states of carbon nanotubes We directly verified the systematic changes in transition energies of semiconducting nanotubes as a function of their chirality and observed predicted energy splittings of optical transitions in metallic nanotubes

Abstract: The peak location of the localized surface plasmon resonance (LSPR) of noble metal nanoparticles is highly dependent upon the refractive index of the nanoparticles' surrounding environment. In this study, new phenomena are revealed by exploring the influence of interacting molecular resonances and nanoparticle resonances. The LSPR peak shift and line shape induced by a resonant molecule vary with wavelength. In most instances, the oscillatory dependence of the peak shift on wavelength tracks with the wavelength dependence of the real part of the refractive index, as determined by a Kramers−Kronig transformation of the molecular resonance absorption spectrum. A quantitative assessment of this shift based on discrete dipole approximation calculations shows that the Kramers−Kronig index must be scaled in order to match experiment.

Abstract: We report high-sensitivity detection of 2,4,6-trinitrotoluene (TNT) by using laser photoacoustic spectroscopy where the laser radiation is obtained from a continuous-wave room temperature high-power quantum cascade laser in an external grating cavity geometry. The external grating cavity quantum cascade laser is continuously tunable over ≈400 nm around 7.3 μm and produces a maximum continuous-wave power of ≈200 mW. The IR spectroscopic signature of TNT is sufficiently different from that of nitroglycerine so that unambiguous detection of TNT without false positives from traces of nitroglycerine is possible. We also report the results of spectroscopy of acetylene in the 7.3-μm region to demonstrate continuous tunability of the IR source.

Abstract: We study many-body interactions between excitons in semiconductors by applying the powerful technique of optical two-dimensional Fourier transform spectroscopy. A two-dimensional spectrum correlates the phase (frequency) evolution of the nonlinear polarization field during the initial evolution and the final detection period. A single two-dimensional spectrum can identify couplings between resonances, separate quantum mechanical pathways, and distinguish among microscopic many-body interactions.

Abstract: Nuclear Magnetic Resonance Spectroscopy. -Introduction. -Properties Of Nuclear Spins. -Nuclear Spin Interactions in Solids. -Quantum Mechanical Calculations. -High Resolution Solid-State NMR Methods. -Principles of 2-Dimensional Spectroscopy. -Molecular Dynamics and Local Molecular Conformation in Solid Materials. -Nuclear Quadrupole Resonance Spectroscopy. -Introduction. -Basic Theory. -Instrumentation. -Interpretation of Coupling Constants. -Summary. -Electron Paramagnetic Resonance Spectroscopy. -Introduction. -Theoretical Background. -Experimental. -Applications of EPR Spectroscopy. ENDOR Spectroscopy. -Introduction. -Experimental Conditions for ENDOR. -ENDOR in The Solid State. -Pulsed ENDOR. -Applications. -Mossbauer Spectroscopy. -Introduction. -Methodology. -Applications. -Concluding Remarks. -Crystal-Field Spectroscopy. -Introduction. -The Crystal-Field Interaction. -Experimental Techniques. -Determination of Crystal-Field Parameters From Experimental Data. -Interactions of Crystal-Field Split Ions. -Crystal-Field Effects Related to High-Temperature Superconductivity. -Concluding Remarks. -Scanning Tunneling Spectroscopy. -Introduction. -The Scanning Tunneling Microscope (STM). -Scanning Tunneling Spectroscopy of Semiconductors & Metals. -Electron Tunneling Spectroscopy of Adsorbed Molecules. -Practical Considerations Relating to STM-IETS and STM-OMTS. -Some Concluding Points. -Resonance Acoustic Spectroscopy. -Introduction. -Scattering Of Waves. -Mathematical Models. -Method of Isolation and Identification of Resonances (MIIR). -Experimental and Numerical Results. -Fourier Transform Infrared Spectroscopy. -Introduction. -Historical Background. -FT-IR Spectroscopy. -Applications. -Auger Electron Spectroscopy. -Introduction. -Historical Perspective. -Basic Principlesof AES. -Instrumentation. -Experimental Procedures Including Sample Preparation. -Auger Spectra: Direct and Derivative Forms. -Applications of Auger Spectroscopy. -Recent Advances. -Conclusions. -X-Ray Photoelectron Spectroscopy. -Introduction And Basic Theory. -Historical Perspective. -Instrumentation. -Sample Selection and Preparation. -Spectral Analysis. -XPS Imaging. -Angle-Resolved XPS. -Recent Advances and Applications. -Conclusions. -Luminescence Spectroscopy. -Introduction. -Spontaneous Emission, Absorption And Induced Emission. -Measurements and Techniques. -Localized Systems. -Processes in Localized System Service. -Delocalized Systems. -Processes in Delocalized Systems. -Direction of Future Efforts. -Laser-Induced Fluorescence Spectroscopy. -Introduction. -Experimental Setup. -Fluorescence Spectroscopy of Minerals. -Fluorescence Spectroscopy of Surface Species and in Solid Phases. -Fluorescence Spectroscopy of Frozen Samples. -Fluorescence Spectroscopy of Non- Actinide Solid Matrices. -Outlook. -Soft X-Ray Emission and Resonant Inelastic Scattering Spectroscopy. -Introduction. -Properties of X-Ray Spectra. -Resonant Inelastic X-Ray Scattering. -Experimental Techniques. -Applications. -Summary. -Laser Raman Spectroscopy. -Introduction. -Spontaneous Raman Scattering. -Experimental Approaches. -Applications. -Conclusions and Outlook. -Polarization Spectroscopy of Ordered Samples. -Introduction. -Occurrence, Production and Optical Properties of Aligned, Solid Samples. -One-Photon Spectroscopy: Linear Dichroism. -Two-Photon Spectroscopy. -Conclusions.