O K-V Spectra of Oxides and Superconducting Materials

1992 ◽  
Vol 36 ◽  
pp. 65-72 ◽  
Author(s):  
Masahiro Sakai ◽  
Shinjiro Hayakawa ◽  
Jun Kawai ◽  
Yohichi Gohshi
Keyword(s):  
Fluorescence Spectra ◽  
Nearest Neighbor ◽  
Emission Spectra ◽  
Cluster Approximation ◽  
X Ray ◽  
Hartree Fock ◽  
Line Shapes ◽  
Orbital Hybridization ◽  
Oxygen Oxygen ◽  
Fluorescence Line

AbstractOxygen K-V (Kα) X-ray fluorescence spectra of MgO, Cu2O, CuO, La2CuO4, La2-xSrxCuO4, YBa2Cu3O7-x , and GdBa2Cu3O7-x are measured. The local (oxygen) and partial (2p) electron density of states (DOS) of these compounds are calculated by the cluster approximation with the discrete variational (DV) Hartree-Fock-Slater (Xα) method. The calculated O 2p DOS are compared with the measured X-ray fluorescence spectra. It is found that the measured 0 K-V X-ray fluorescence line shapes are well reproduced by the O 2p DOS calculated by a cluster including the second nearest neighbor atoms (oxygen atoms) in the solids. This indicates that the oxygen K-V X-ray emission spectra reflect the oxygen-oxygen orbital hybridization in the solid as well as the oxygen-metal orbital hybridization.

scholarly journals Investigation of Y2.1Er0.9(ScxGa1−x)5O12 Matrix Components on the Spectral Properties around 3.0 μm by Micro-Pulling-Down Method

Crystals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 138
Author(s):  
Zhijiang Che ◽  
Jian Zhang ◽  
Baiyi Wu ◽  
Qiangqiang Hu ◽  
Wenxiang Mu ◽  
...  
Keyword(s):  
Fluorescence Spectra ◽  
Room Temperature ◽  
Lattice Vibration ◽  
Emission Spectra ◽  
X Ray Diffraction ◽  
Mid Infrared ◽  
X Ray ◽  
Electron Probe Microanalyzer ◽  
The Matrix ◽  
Crystal Fibers

Single crystal fibers of 30% Er3+-doped compound of Y3(ScxGa1−x)5O12 have been grown by using the micro-pulling down (μ-PD) technique successfully. Our main purpose is to tune the fluorescence properties by adjusting the ratios of Sc3+ and Ga3+ ions inside the matrix crystals. The crystal structures of the series compounds were measured and analyzed through X-ray diffraction (XRD) measurements. The components and doping elements distributions were measured by the X-ray Fluorescence spectrometry and electron-probe microanalyzer. The absorption and mid-infrared fluorescence spectra, including the fluorescent lifetime of Er3+:4I13/2 and 4I11/2 levels were measured and compared systematically at room temperature. Spectral analysis indicated that the fluorescent lifetime of Er3+:4I13/2 tended to shorten and the emission spectra began to show a red shift when the proportion of YSG increased in the compound. Furthermore, the Raman spectra were measured to reveal the variations of lattice vibration and phonon energy.

X-RAY SPECTROSCOPIC ANALYSIS OF BORON-NITRIDE CLUSTERS DEPOSITED BY ION-PLATING METHOD

1996 ◽  
Vol 03 (01) ◽  
pp. 1051-1057 ◽  
Author(s):  
H. KOHZUKI ◽  
M. MOTOYAMA ◽  
T. KANEYOSHI ◽  
Y. KOWADA ◽  
J. KAWAI ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Emission Spectrum ◽  
Cubic Boron Nitride ◽  
Emission Spectra ◽  
Satellite Peak ◽  
X Ray ◽  
Ion Plating ◽  
Hartree Fock ◽  
Plating Method ◽  
Diffraction Patterns

Cubic boron-nitride (c-BN) films were deposited on a silicon substrate by varying the deposition time, using a reactive ion-plating method. In order to investigate the growth mechanism of c-BN films, these c-BN films were characterized by x-ray emission spectra of boron (B K x-ray emission spectra), infrared absorption spectra, selected area diffraction patterns, and TEM microstructures. It was found that the BN film with sp2 bonding formed initially on the substrate and subsequently c-BN film formed. The c-BN film was composed of fine crystallites with a size of about 10 nm and with random orientation. In the case of the B K x-ray emission spectrum from the BN film with sp 2 bonding, the intensity of the satellite peak at the short-wavelength side was extremely stronger than that of sp 2-bonded BN-like turbostratic or hexagonal BN. As a result of calculation of the B K x-ray emission spectrum of BN using the discrete variational Hartree-Fock-Slater (DV-Xα) method, it was found that the satellite peak intensity increased with formation of the fine BN cluster having two-coordinated boron (which has a dangling bond) and with decreasing size of the cluster. Therefore, it is considered that the BN film with sp 2 bonding was composed of the very fine BN cluster having two-coordinated borons, and became the precursor of c-BN film at the interface between the substrate and c-BN film.

scholarly journals X-ray Emission Spectra of Some Carbon-containing Molecules

1986 ◽  
Vol 39 (5) ◽  
pp. 717 ◽  
Author(s):  
RA Phillips ◽  
FP Larkins
Keyword(s):  
Transition Probabilities ◽  
Emission Spectra ◽  
Fluorescence Yield ◽  
Total Carbon ◽  
Molecular Orbital Calculations ◽  
Electronic Relaxation ◽  
X Ray ◽  
Hartree Fock ◽  
Relaxation Effects ◽  
Absolute Transition

Ab initio molecular orbital calculations for the energy and intensity of X-ray transitions associated with the carbon monoxide, hydrogen cyanide and carbon dioxide molecules have been calculated at the Hartree-Fock level. It is demonstrated that in general the absolute transition probabilities are sensitive to the inclusion of electronic relaxation effects and interatomic transition moment contributions. It is concluded that calculations for molecular X-r!ly emission henomena should be undertaken at least at the multicentre relaxed Hartree-Fock level to achieve a realistic basis for comparison with experiment. Total carbon-K X-ray rates do not show a strong variation with changes in the molecular environment. The total rates are of a similar magnitude to those reported for the atom. The calculated carbon-K fluorescence yield is also similar in both the carbon atom and the CO2 molecule.

HEAVY ION-INDUCED COPPER L X-RAY SPECTRA MEASURED WITH A HIGH RESOLUTION X-RAY CRYSTAL SPECTROMETER

1997 ◽  
Vol 07 (03n04) ◽  
pp. 109-115 ◽  
Author(s):  
K. KAWATSURA ◽  
T. INOUE ◽  
T. IGARASHI ◽  
N. TERAZAWA ◽  
S. ARAI ◽  
...  
Keyword(s):  
High Resolution ◽  
Emission Spectra ◽  
Heavy Ion ◽  
Thick Target ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Hartree Fock ◽  
Ion Impact ◽  
Electron Vacancy ◽  
Shell Vacancy

High resolution L X-ray emission spectra of Cu have been measured for 0.75 MeV/u H , 0.075 and 0.75 MeV/u F , and 0.075 and 0.64 MeV/u Si ion impacts with a Bragg crystal spectrometer. The high resolution X-ray spectra from the Cu thick target for L ι, L η, L α1,2, L β1, and L β3,4 transitions induced by ion excitation are obtained. The X-ray spectra produced by F and Si ion impacts have complicated structures due to multiple L and M shell vacancy production. The L X-ray emission spectra produced by heavy ion impact are compared with the calculated ones based on the Hartree-Fock-Slater method. The origin of the broadening of the L X-ray transition lines to the higher energy side for heavy ion impact is attributed to one 2p plus multiple 3p and 3d electron vacancy production.

Raman And Fluorescence Spectra Observed in Laser Microprobe Measurements of Several Compositions in the Ln-Ba-Cu-O System

1990 ◽  
Vol 48 (2) ◽  
pp. 278-279
Author(s):  
Edgar S. Etz ◽  
Thomas D. Schroeder ◽  
Winnie Wong-Ng
Keyword(s):  
Fluorescence Spectra ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Raman Microprobe ◽  
Methods Of Synthesis ◽  
Compositional Homogeneity ◽  
Processing Techniques

We are investigating by Raman microprobe measurements the superconducting and related phases in the LnBa2Cu3O7-x (for x=0 to 1) system where yttrium has been replaced by several of the lanthanide (Ln = Nd,Sm,Eu,Ho,Er) elements. The aim is to relate the observed optical spectra (Raman and fluorescence) to the compositional and structural properties of these solids as part of comprehensive materials characterization. The results are correlated with the methods of synthesis, the processing techniques of these materials, and their superconducting properties. Of relevance is the substitutional chemistry of these isostructural systems, the differences in the spectra, and their microanalytical usefulness for the detection of impurity phases, and the assessment of compositional homogeneity. The Raman spectra of most of these compounds are well understood from accounts in the literature.The materials examined here are mostly ceramic powders prepared by conventional solid state reaction techniques. The bulk samples are of nominally single-phase composition as determined by x-ray diffraction.

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

EXPERIMENTAL AND THEORETICAL SOFT X-RAY EMISSION SPECTRA OF Cu-Pd SUBSTITUTIONAL ALLOYS

1987 ◽  
Vol 48 (C9) ◽  
pp. C9-1059-C9-1062
Author(s):  
P. J. DURHAM ◽  
C. F. HAGUE ◽  
J.-M. MARIOT ◽  
W. M. TEMMERMAN
Keyword(s):  
Emission Spectra ◽  
X Ray ◽  
Substitutional Alloys
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