Relative intensities of low-energy plasmon satellites in x-ray emission spectra of Li, Be, and Na

1976 ◽  
Vol 13 (7) ◽  
pp. 3213-3214 ◽  
Author(s):  
K. S. Srivastava ◽  
S. P. Singh ◽  
R. L. Shrivastava
Keyword(s):  
Emission Spectra ◽  
Low Energy ◽  
X Ray

Valence Band Spectroscopy in the Ultrasoft X-Ray Region (50 to 100 A)

1975 ◽  
Vol 19 ◽  
pp. 627-641 ◽  
Author(s):  
Burton L. Henke ◽  
Kazuo Taniguchi
Keyword(s):  
Measurement Method ◽  
Emission Spectra ◽  
Sample Surface ◽  
Electron Excitation ◽  
Low Energy ◽  
High Dispersion ◽  
Simple Method ◽  
X Ray ◽  
Molecular Layers ◽  
Illustrative Application

Transitions from the valence electron levels into the first relatively sharp inner sub-shell levels result in characteristic x-ray emissions in the 100-200 eV region. These spectra sensitively reflect the chemical state of the atoms which are representative of the submicron thickness of the sample surface under low energy x-ray excitation and of the first few molecular layers of the sample under electron excitation.An optimized measurement method for this 50-100 A spectral region is “based upon single crystal spectrometry using a lead stearate analyzer which has high dispersion and efficiency and an energy width of about one eV in this wavelength range. Spectra are recorded using “tuned” proportional counter detection. In the work reported here, low energy x-ray excitation is used in order to minimize the possibility of radiation damage of the sample.Each spectrum is calibrated for both energy and instrument transmission using known, sharp M lines of elements such as molybdenum, zirconium and yttrium which will bracket the spectraj. range under measurement. A simple method has been developed for "stripping" from the measured spectra the Lorentzian crystal width and the Gaussian collimation width in order to allow an estimation to be made of the actual emission line widths as well as the relative intensities.In this report, as an illustrative application example, S-LII, III spectra are presented for a series of sulfur compounds in "both solid, and gas states. Manne's approximate molecular orbital interpretation of the x-ray emission spectra has been adopted and extended to apply to the LII, III spectra for second row elements.

Intensity of Low Energy Plasmon Satellite Band in Soft X-Ray Emission Spectra

1974 ◽  
Vol 63 (1) ◽  
pp. K25-K27 ◽  
Author(s):  
K. S. Srivastava ◽  
S. P. Singh ◽  
R. L. Shrivastava
Keyword(s):  
Emission Spectra ◽  
Low Energy ◽  
X Ray

High-resolution silicon Kβ X-ray spectra and crystal structure

1989 ◽  
Vol 53 (370) ◽  
pp. 239-244 ◽  
Author(s):  
J. Purton ◽  
D. S. Urch
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Molecular Orbital ◽  
Local Structure ◽  
Emission Spectra ◽  
High Energy ◽  
Low Energy ◽  
Photoelectron Spectra ◽  
Peak Width ◽  
X Ray

AbstractHigh-resolution X-ray emission spectra (XES) are presented for minerals with a variety of structures. The participation of the Si 3p orbitals in bonding is influenced by the local structure around the silicon atom. In orthosilicates the distortion of the SiO44--tetrahedron influences both peak-width and the intensity of the high-energy shoulder of the Si-Kβ spectrum. In minerals containing Si-O-Si bonds there is mixing of the Si 3s and 3p orbitals giving rise to a peak on the low-energy side of the main Si-Kβ peak. When combined with X-ray photoelectron spectra (XPS), a complete molecular orbital picture of bonding can be established.

Chemical Bonding Effects in X-Ray Emission Spectra - A Molecular Orbital Model

1970 ◽  
Vol 14 ◽  
pp. 250-267 ◽  
Author(s):  
David S. Urch
Keyword(s):  
Molecular Orbital ◽  
Atomic Orbital ◽  
Energy Levels ◽  
Emission Spectra ◽  
Peak Shift ◽  
Low Energy ◽  
Molecular Orbital Theory ◽  
Orbital Theory ◽  
X Ray ◽  
Tetrahedral Unit

AbstractMolecules or ions usually exist as discrete units, in crystals of chemical compounds. Intermolecular or interionic coValent interactions are slight so the bond structure of such, solids is very similar to the pattern of energy levels in each individual molecule or ion. Simple molecular orbital theory can therefore be used to generate a qualitative picture of the energy levels in a molecule or an ion; and this picture can then be used directly to interpret X-ray emission spectra. The application of molecular orbital theory, using group theory to simplify the calculations is described for a tetrahedral unit ML4. The origin of peak shifts and of low-energy satellite peaks are rationalised. A consideration of orbital amplitudes shows that the ‘cross-over' theory of O'Brien and Skinner cannot explain the observed intensities of low-energy satellite peaks. It is suggested that the use of the M. 0. model for the interpretation of X-ray emission spectra permits far greater analytical and structural use to be made of peak shift and satellite data. Ligands can be identified even when their own characteristic emissions are not detected (e.g. oxygen and fluorine). Relative peak intensities can be correlated with atomic orbital participation in bond formation. Such information is of great interest to chemists and can often be used to identify the bonding r61e of specific orbitals (e.g. the 3d orbitals of second row, main group, elements).

Advances in Low-Energy Electron-Induced X-Ray Spectroscopy (LEEIXS)

1980 ◽  
Vol 24 ◽  
pp. 351-361
Author(s):  
René Bador ◽  
Maurice Romand ◽  
Marlène Charbonnier ◽  
Alain Roche
Keyword(s):  
Surface Composition ◽  
Emission Spectra ◽  
Low Energy ◽  
Energy Electron ◽  
Anodic Films ◽  
X Ray ◽  
Advantages And Disadvantages ◽  
Cathode Tube ◽  
Carbon Impurities ◽  
Low Energy Electron

AbstractUsing low-energy electron induced X-ray spectroscopy (LEEIXS) with a cold cathode tube as excitation source and appropriate calibrations, quantitative surface composition informations are obtained. The results concern anodic film thicknesses and carbon impurities, In addition, qualitative informations on the chemical state of the film components are deduced from the fine structure of X-ray emission bands. The results concern oxygen K emission spectra from CuO and Cu2O, SnO, SnO2 and anodized Sn. It is also shown the capabilities of LEEIXS for gaining element-depth profiles, One example pertaining to phosphorus impurities in Al2O3 anodic films is given. Finally advantages and disadvantages of LEEIXS over ion-induced X-ray spectroscopy are discussed.

Nano-probe x-ray analysis and high-resolution imaging on planar defects in high-pressure synthesized infinite-layer superconductor

1994 ◽  
Vol 52 ◽  
pp. 728-729
Author(s):  
Y. Y. Wang ◽  
H. Zhang ◽  
V. P. Dravid ◽  
H. Zhang ◽  
L. D. Marks ◽  
...  
Keyword(s):  
High Pressure ◽  
High Resolution ◽  
Atomic Structure ◽  
Emission Spectra ◽  
High Resolution Electron Microscopy ◽  
Planar Defects ◽  
X Ray ◽  
Infinite Layer ◽  
Resolution Electron ◽  
Resolution Imaging

Azuma et al. observed planar defects in a high pressure synthesized infinitelayer compound (i.e. ACuO2 (A=cation)), which exhibits superconductivity at ~110 K. It was proposed that the defects are cation deficient and that the superconductivity in this material is related to the planar defects. In this report, we present quantitative analysis of the planar defects utilizing nanometer probe xray microanalysis, high resolution electron microscopy, and image simulation to determine the chemical composition and atomic structure of the planar defects. We propose an atomic structure model for the planar defects.Infinite-layer samples with the nominal chemical formula, (Sr1-xCax)yCuO2 (x=0.3; y=0.9,1.0,1.1), were prepared using solid state synthesized low pressure forms of (Sr1-xCax)CuO2 with additions of CuO or (Sr1-xCax)2CuO3, followed by a high pressure treatment.Quantitative x-ray microanalysis, with a 1 nm probe, was performed using a cold field emission gun TEM (Hitachi HF-2000) equipped with an Oxford Pentafet thin-window x-ray detector. The probe was positioned on the planar defects, which has a 0.74 nm width, and x-ray emission spectra from the defects were compared with those obtained from vicinity regions.

Self-Consistent Field Calculations of X-Ray Emission Spectra of Surface Adsorbates and Polymers

1997 ◽  
Vol 7 (C2) ◽  
pp. C2-515-C2-516
Author(s):  
H. Agren ◽  
L. G.M. Pettersson ◽  
V. Carravetta ◽  
Y. Luo ◽  
L. Yang ◽  
...  
Keyword(s):  
Emission Spectra ◽  
X Ray ◽  
Consistent Field ◽  
Self Consistent ◽  
Surface Adsorbates ◽  
Self Consistent Field
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