scholarly journals Soft x-ray emission spectra of lithium fluoride excited by synchrotron radiation

1986 ◽  
Author(s):  
K.L. Tsang ◽  
C.H. Zhang ◽  
T.A. Callcott ◽  
E.T. Arakawa ◽  
D.L. Ederer
2013 ◽  
Vol 93 ◽  
pp. 82-86 ◽  
Author(s):  
Krzysztof Banas ◽  
Agnieszka M. Banas ◽  
Mariusz Gajda ◽  
Wojciech M. Kwiatek ◽  
Bohdan Pawlicki ◽  
...  

2011 ◽  
Vol 83 (4) ◽  
Author(s):  
W. Cao ◽  
M. Kavčič ◽  
J.-Cl. Dousse ◽  
M. Berset ◽  
K. Bučar ◽  
...  

1993 ◽  
Vol 307 ◽  
Author(s):  
K. E. Miyano ◽  
W. L. O'Brien ◽  
D. L. Ederer ◽  
T. A. Callcott ◽  
J. J. Jia ◽  
...  

ABSTRACTMonochromatized synchrotron radiation has been employed as the excitation source for soft x-ray emission spectroscopy. In the present paper changes in the emission spectra that occur as the excitation energy is varied near the core-absorption threshold are discussed. In the case of crystalline silicon, strong variations are seen in the L2,3 emission for excitation energies up to 30 eV above threshold. These variations are shown to be dependent on the crystalline order of the material and can be interpreted in terms of restrictions on the crystal momentum that arise in an inelastic scattering description of the combined absorption and emission. On the other hand this description is less relevant to the excitation-energy dependence of ionic insulators, in which strong phonon coupling removes these restrictions on crystal momentum. In the insulators B2O3 and BN strong variations in the emission are observed at threshold, upon creation of a core exciton: the exciton affects the emission through its influence on the phonon coupling as well as on the initial and final-state screening.


1971 ◽  
Vol 32 (C4) ◽  
pp. C4-331-C4-333 ◽  
Author(s):  
K. FESER ◽  
J. MÜLLER ◽  
G. WIECH ◽  
A. FAESSLER

1994 ◽  
Vol 348 ◽  
Author(s):  
Andrey N. Belsky ◽  
Vitaly V. Mikhaihin ◽  
Andrey L. Rogalev ◽  
Eduard I. Zinin

ABSTRACTThe time-resolved luminescence spectra and decay kinetics of BaF2, BGO, and CeF3, were measured with the dissector technique using X-ray synchrotron radiation (SR)of different spectral composition from wiggler mounted at VEPP-3 storage ring (Novosibirsk).Two effects of X-ray excitation energy on the luminescence parameters were observed: modifications of the emission spectrum and acceleration of decay kinetics. Under the excitation by soft X-ray SR the 220 nm emission band for BaF2 is broadened, whereas shorter wavelength part of CeF3 and BGO emission spectra increases. For luminescence decay of excitons and crossluminescence the degree of the deviation from the single exponential law depends on the photon energies and increases under soft X-ray excitation as well. These effects are supposed to be due to the interaction of electronic excitations created after the relaxation of deep core holes.Fast intrinsic luminescence was observed for Cdl2, and CsPbCl3 under X-ray SR excitation. 500 nm band of Cdl2 has characteristic time τ=4.6 ns, whereas 420 nm band of CsPbCl3 shows very fast decay with τ=0.2 ns.


1987 ◽  
Vol 35 (16) ◽  
pp. 8374-8377 ◽  
Author(s):  
K. L. Tsang ◽  
C. H. Zhang ◽  
T. A. Callcott ◽  
E. T. Arakawa ◽  
D. L. Ederer

Author(s):  
Y. Y. Wang ◽  
H. Zhang ◽  
V. P. Dravid ◽  
H. Zhang ◽  
L. D. Marks ◽  
...  

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.


Author(s):  
B. Jouffrey ◽  
D. Dorignac ◽  
A. Bourret

Since the early works on GP zones and the model independently proposed by Preston and Guinier on the first steps of precipitation in supersaturated solid solution of aluminium containing a few percent of copper, many works have been performed to understand the structure of different stages in the sequence of precipitation.The scheme which is generally admitted can be drawn from a work by Phillips.In their original model Guinier and Preston analysed a GP zone as composed of a single (100) copperrich plane surrounded by aluminum atomic planes with a slightly shorter distance from the original plane than in the solid solution.From X-ray measurements it has also been shown that GP1 zones were not only copper monolayer zones. They could be up to a few atomic planes thick. Different models were proposed by Guinier, Gerold, Toman. Using synchrotron radiation, proposals have been recently made.


1997 ◽  
Vol 7 (C2) ◽  
pp. C2-515-C2-516
Author(s):  
H. Agren ◽  
L. G.M. Pettersson ◽  
V. Carravetta ◽  
Y. Luo ◽  
L. Yang ◽  
...  

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