Discrete-continuum interaction for the core-hole state of water

1988 ◽  
Vol 148 (2-3) ◽  
pp. 210-214 ◽  
Author(s):  
Vincenzo Carravetta ◽  
Hans Ågren ◽  
Amary Cesar
Keyword(s):  
The Core ◽  
2000 ◽  
Vol 14 (11) ◽  
pp. 1139-1177 ◽  
Author(s):  
RYUTARO SOUDA

In this article, the mechanism of electronic transitions during scattering and stimulated desorption of ions from solid surfaces is discussed. Reactive ions such as H + and O + experience transient chemisorption during scattering from solid surfaces. These ions are neutralized almost completely on metal and semiconductor surfaces due to the band effect on resonance neutralization. The neutralization probability of H + is suppressed considerably on highly ionic compound surfaces and is dependent on the target species due to the formation of the bound state (on cations) or the surface molecule (on anions). Because of this, the H - ion is formed preferentially on the cationic site rather than on the anionic site. The noble-gas ions are neutralized via the Auger process so that the neutralization probability is basically independent of the band effect. The stimulated desorption of secondary O + and F + ions does not exhibit the band effect. This is because the desorption is initiated by the core hole state, which is followed by ionization via the intra-atomic Auger decay after breakage of the chemisorptive bond. The stimulated desorption of H + might occur from the valence holes but is more likely to be caused by the core-excited OH species via the interatomic Auger decay. The core hole is created not only by the electron and photon irradiation but also by the energetic ion bombardment due to the nonadiabatic transition of the primary ion/s core hole. Also presented are some applications of ion scattering and ion stimulated desorption for the analysis of the diffusion/segregation dynamics of oxygen and hydrogen on solid surfaces.


2019 ◽  
Vol 26 (1) ◽  
pp. 152-158 ◽  
Author(s):  
Ondřej Šipr ◽  
Wilayat Khan ◽  
Yves Joly ◽  
Ján Minár

Ca and S K-edge spectra of CaS are calculated by the full-potential Green's function multiple-scattering method, by the FLAPW method and by the finite-difference method. All three techniques lead to similar spectra. Some differences remain close to the edge, both when comparing different calculations with each other and when comparing the calculations with earlier experimental data. Here it is found that using the full potential does not lead to significant improvement over the atomic spheres approximation and that the effect of the core hole can be limited to the photoabsorbing atom alone. Doping CaS with Eu will not affect the Ca and S K-edge XANES of CaS significantly but may give rise to a pre-edge structure not present for clean CaS.


1977 ◽  
Vol 99 (24) ◽  
pp. 8120-8121 ◽  
Author(s):  
D. T. Clark ◽  
B. J. Cromarty ◽  
L. Colling

2013 ◽  
Vol 27 (16) ◽  
pp. 1330012 ◽  
Author(s):  
A. KOTANI

We consider two different resonant X-ray emission spectra for Ce compounds: Ce 3d to 2p X-ray emission (denoted by 3d-RXES) and valence to 2p X-ray emission (v-RXES), both of which follow the Ce 2p to 5d resonant excitation. We propose that the comparison of the 3d- and v-RXES spectra is a new powerful method of directly detecting the core-hole effect in the final state of Ce L 3 X-ray absorption spectra (XAS). We applied this method to recent experimental RXES spectra for CeO 2 and CeFe 2, and showed unambiguously that the core-hole effect should be essential in the XAS of both materials. This result is confirmed by theoretical calculations, which reproduce well the experimental RXES and XAS spectra. We conclude that the ground state of CeO 2 is in the mixed state of 4f0 and [Formula: see text] configurations, where [Formula: see text] is a ligand hole, instead of a pure 4f0 configuration which was proposed recently by first-principles energy band calculations. Also, we conclude that the double peaks observed in L 3 XAS of CeFe 2 are caused by the 4f0 and 4f1 configurations, which are mixed in the ground state but separated in energy by the large core-hole potential in the final state of XAS.


1994 ◽  
Vol 348 ◽  
Author(s):  
Andrey N. Belsky ◽  
Irina A. Kamenskikh ◽  
Andrey N. Vasil'ev ◽  
Alexander V. Gektin ◽  
Christian Pedrini ◽  
...  

ABSTRACTThe Auger decay of a core hole results in appearance of several strongly correlated excitations. This excited region strongly polarizes the lattice and thus the defect creation is possible. In all cases the core hole causes the strong local perturbation of electronic and lattice subsystems. The creation of such excited region with mutual relaxation of correlated electrons and holes can result in the increase of the efficiency of energy transfer to activators, acceleration of the luminescence kinetics, and the appearance of radiation-induced luminescence centers.


2014 ◽  
Vol 171 ◽  
pp. 93-111 ◽  
Author(s):  
Bridgette Cooper ◽  
Přemysl Kolorenč ◽  
Leszek J. Frasinski ◽  
Vitali Averbukh ◽  
Jon P. Marangos

Ultrafast hole dynamics created in molecular systems as a result of sudden ionisation is the focus of much attention in the field of attosecond science. Using the molecule glycine we show through ab initio simulations that the dynamics of a hole, arising from ionisation in the inner valence region, evolves with a timescale appropriate to be measured using X-ray pulses from the current generation of SASE free electron lasers. The examined pump–probe scheme uses X-rays with photon energy below the K edge of carbon (275–280 eV) that will ionise from the inner valence region. A second probe X-ray at the same energy can excite an electron from the core to fill the vacancy in the inner-valence region. The dynamics of the inner valence hole can be tracked by measuring the Auger electrons produced by the subsequent refilling of the core hole as a function of pump–probe delay. We consider the feasibility of the experiment and include numerical simulation to support this analysis. We discuss the potential for all X-ray pump-X-ray probe Auger spectroscopy measurements for tracking hole migration.


1992 ◽  
Vol 164 (1) ◽  
pp. 73-82 ◽  
Author(s):  
P. Decleva ◽  
M. Ohno
Keyword(s):  
The Core ◽  

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