scholarly journals Оптические сечения поглощения и силы осцилляторов двойного донора магния в кремнии

Author(s):  
Ю.А. Астров ◽  
Л.М. Порцель ◽  
В.Б. Шуман ◽  
А.Н. Лодыгин ◽  
Н.В. Абросимов ◽  
...  

The optical properties of magnesium impurity in silicon, whose atoms at interstitial positions in the lattice are deep double donors with an ionization energy of 107.56 meV in the neutral state, were studied. For optical transitions from the ground state of a neutral center to the excited levels 2p0 and 2p, the absorption cross sections and oscillator strengths were determined. These parameters were calculated from the impurity absorption spectra that were measured at T  K in samples with different magnesium concentrations. The deep donor content in the samples was determined using Hall effect measurements in the temperature range 78–300 K. The obtained characteristics of intracenter transitions in magnesium were compared with the corresponding literature data for shallow Group V donors in silicon, which are substitutional impurities. It was found that the optical characteristics of the investigated transitions in magnesium are consistent with the dependences of the corresponding parameters on the ionization energy for shallow donors, extrapolated to the region of larger electron binding energies.

1988 ◽  
Vol 53 (3) ◽  
pp. 425-432 ◽  
Author(s):  
Zdeněk Bastl ◽  
Heidrun Gehlmann

The core electron binding energies of eighteen compounds containing iodine in different oxidation states ranging from (-I) to (VII) have been measured. The observed chemical shifts differ from the literature data. The anticipated existence of hexavalent iodine in certain compounds has not been demonstrated. The relative subshell photoemission intensities of iodine have been determined. Empirically derived atomic sensitivity factors and theoretical photoionization cross-sections have been used to calculate the surface stoichiometry. The concentration ratios obtained via the two methods are compared. In agreement with generally accepted view the results of this comparison imply that, for quantitative surface analysis, empirical values should be used rather than theoretical data.


2021 ◽  
Vol 2103 (1) ◽  
pp. 012030
Author(s):  
I V Demidov ◽  
A Y Potekhin

Abstract Magnetar atmospheres can contain a substantial fraction of once-ionized helium. At the magnetic fields about 1014 −1015 G, typical of magnetars, Landau quantization is important not only for the electrons, but also for the centre-of-mass (CM) motion of the He+ ion. The CM and internal motions are mutually dependent, which complicates theoretical studies of the He+ characteristics. We present asymptotic analytic expressions for the binding energies, oscillator strengths, and photoionization cross sections of the moving hydrogenlike ions in an ultra-strong magnetic field, which can be used to construct approximate models of magnetar atmospheres.


1987 ◽  
Vol 42 (9) ◽  
pp. 943-947
Author(s):  
I. Agil ◽  
A. Alharkan ◽  
H . Alhendi ◽  
A. Alnaghmoosh

It is shown that leading corrections, to the ionization energy, of many-electrons atom, can be expressed as leading corrections of initial slope of trial variational solutions of the Thomas-Fermi equation. Some variational solutions with different initial slopes are compared. A comparison of the results shows, that as far as the binding energies are concerned a trial function with its slope not close to the (negative) Baker’s constant may not be suited.


1985 ◽  
Vol 63 (3) ◽  
pp. 417-427 ◽  
Author(s):  
Ashok Kumar ◽  
William J. Meath

Dipole oscillator strength distributions have been constructed and used to evaluate integrated oscillator strengths, and a variety of dipole oscillator strength properties, for ground state SO2, CS2, and OCS. Each distribution has been constructed by using experimental and theoretical photoabsorption cross sections and by subjecting the resulting dipole oscillator strength data to constraints provided by the Thomas–Reiche–Kuhn sum rule and molar refractivity data for the relevant dilute gases. The discussion includes graphical presentations of how various spectral regions of the dipole oscillator strength distributions contribute to the more important dipole properties.


2013 ◽  
Vol 112 (3-4) ◽  
pp. 332-339 ◽  
Author(s):  
O. Dolgounitcheva ◽  
V.G. Zakrzewski ◽  
L. Streit ◽  
J.V. Ortiz

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