Search results for " Spectra"
showing 10 items of 709 documents
Estimation of line parameters under line mixing effect: the nu3 band of CH4 in helium
2001
International audience; Spectra of CH4-He mixtures were measured in the P and R branch regions of nu3 vibration-rotation band at lower pressures of 0.26-1.0 bar and for the whole band at higher pressures up to 90 bar. The line broadening coefficients were found from lower pressure data for the lines of the P branch. These coefficients were calculated in the framework of the Robert and Bonamy semi-classical approach. In general, they agree with the experimental ones, but a small J-dependent deviation was observed. Line mixing effects were observed at all pressures. At higher pressures they were interpreted in terms of the adjusted branch-coupling model. At lower pressures line mixing effects…
Using the methods of radiospectroscopy (EPR, NMR) to study the nature of the defect structure of solid solutions based on lead zirconate titanate (PZ…
2014
The nature of intrinsic and impurity point defects in lead zirconate titanate (PZT) ceramics has been explored. Using electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS) methods, several impurity sites have been identified in the materials, including the Fe 3+ -oxygen vacancy (VO) complex and Pb ions. Both of these centers are incorporated into the PZT lattice. The Fe 3+ -V paramagnetic complex serves as a sensitive probe of the local crystal field in the ceramic; the symmetry of this defect roughly correlates with PZT phase diagram as the composition is varied from PbTiO 3 to PbZrO 3 . NMR spectra 207 Pb in PbTiO 3 , PbZrO 3 ,…
Recent advances on physico-chemical characterization of passive films by EIS and differential admittance techniques
2007
Abstract Thin Nb2O5 anodic films (∼20 nm thick) grown in phosphoric acid solution have been characterised by EIS and differential admittance study in a large range of potential and frequency. The overall electrical behaviour has been interpreted by means of the theory of amorphous semiconductor Schottky barrier in presence of a non-constant density of states (DOS). A comparison of DOS for films grown in different electrolytes is reported.
Correction: Calculation of vibrationally resolved absorption and fluorescence spectra of the rylenes
2020
Correction for ‘Calculation of vibrationally resolved absorption and fluorescence spectra of the rylenes’ by Jonas Greiner et al., Phys. Chem. Chem. Phys., 2020, 22, 2379–2385.
Thin film growth and band lineup of In2O3 on the layered semiconductor InSe
1999
Thin films of the transparent conducting oxide In2O3 have been prepared in ultrahigh vacuum by reactive evaporation of indium. X-ray diffraction, optical, and electrical measurements were used to characterize properties of films deposited on transparent insulating mica substrates under variation of the oxygen pressure. Photoelectron spectroscopy was used to investigate in situ the interface formation between In2O3 and the layered semiconductor InSe. For thick In2O3 films a work function of φ = 4.3 eV and a surface Fermi level position of EF−EV = 3.0 eV is determined, giving an ionization potential IP = 7.3 eV and an electron affinity χ = 3.7 eV. The interface exhibits a type I band alignmen…
Photothermal excitation setup for a modified commercial atomic force microscope
2014
High-resolution imaging in liquids using frequency modulation atomic force microscopy is known to suffer from additional peaks in the resonance spectrum that are unrelated to the cantilever resonance. These unwanted peaks are caused by acoustic modes of the liquid and the setup arising from the indirect oscillation excitation by a piezoelectric transducer. Photothermal excitation has been identified as a suitable method for exciting the cantilever in a direct manner. Here, we present a simple design for implementing photothermal excitation in a modified Multimode scan head from Bruker. Our approach is based on adding a few components only to keep the modifications as simple as possible and …
Optical and Vibrational Spectra of CsCl-Enriched GeS2-Ga2S3 Glasses
2016
Optical and FTIR spectroscopy was employed to study the properties of 80GeS2-20Ga2S3-CsCl chalcohalide glasses with CsCl additives in a temperature range of 77–293 K. It is shown that CsCl content results in the shift of fundamental absorption edge in the visible region. Vibrational bands in FTIR spectra of (80GeS2-20Ga2S3)100 − х (СsCl) x (x = 5, 10, and 15) are identified near 2500 cm−1, 3700 cm−1,, around 1580 cm−1, and a feature at 1100 cm−1. Low energy shifts of vibrational frequencies in glasses with a higher amount of CsCl can be caused by possible thermal expansion of the lattice and nanovoid agglomeration formed by CsCl additives in the inner structure of the Ge-Ga-S glass.
Transmission properties at microwave frequencies of two-dimensional metallic lattices
1999
The transmission properties of different metallic photonic lattices (square and rectangular) have been experimentally studied. A numerical algorithm based on time domain finite differences has been used for simulating these photonic structures. The introduction of defects in the two-dimensional metallic lattice modifies its transmission spectrum. If metal rods are eliminated from (or added to) the lattice, extremely narrow peaks are observed at some particular frequencies below (or above) the band pass edge. Vicente.Such@uv.es ; Enrique.Navarro@uv.es
Influence of low power CW laser irradiation on skin hemoglobin changes
2012
Influence of low power laser irradiance on healthy skin using diffuse reflectance spectroscopy and multispectral imaging was studied. Changes of diffuse reflectance spectra in spectral range from 500 to 600 nm were observed after 405 nm, 473 nm and 532 nm laser provocation, leading to conclusion that the content of skin hemoglobin has changed. Peaks in spectral absorbance (optical density) curves corresponded to well-known oxy-hemoglobin absorbance peaks at 542 and 577 nm.
Fabrication of long period fiber gratings of subnanometric bandwidth.
2017
This paper reports on the fabrication of long period fiber gratings having subnanometric bandwidth in the 1500 nm spectral region. Large gratings have been photo-inscribed in a high NA fiber, the grating pitch and the order of the HE cladding mode are optimized to produce gratings with a large number of periods and preventing the coupling to TE, TM or EH modes. Resonances with a FWHM of 0.83 nm and 0.68 nm have been achieved for gratings 15 and 20 cm long respectively, the free spectral range between transmission notches is 125 nm. The polarization effects and the sensitivity of the gratings to temperature and to strain variations are presented as well. © 2015 Optical Society of America Thi…