Sensing the Auger Spectra for Solids: New Quantum Approach

Abstract

SENSING THE AUGER SPECTRA FOR SOLIDS: NEW QUANTUM APPROACH S. V. Ambrosov, A. V. Glushkov, L. V. NikolaIt is proposed new approach to sensing Auger spectra of solids and calculation of charac-teristics of Auger decay within S-matrix Gell-Mann and Low formalism. The energies of Auger electron transitions in solids (Na,Si,Ge,Ag) are calculated with account for correlation effects.

Theoretical Auger Spectroscopy of Solids: Calculation of Energy Parameters

“…In addition, the proportionality coefficient in the equation coincides with the electron impact ionization cross-section σ ϳ of the level ϳ. Of course, two aspects are to be considered when determining the exit probability of Auger electrons from an atom, namely, the radiative transition under neutralization of a hole at the level j and the possibility of a considerable change in the initial hole distribution at the core levels at the Auger decay via the radiative channel jkl associated as a rule with a considerable distinctions in the non-radiative transition probabilities [11,12]. For definiteness sake, let the ionization of L levels in a multi-electron atom be considered.…”

“…The Auger line intensity is defined by three atomic constants: А jkl = σ ϳ f ϳ a ϳkl where a ϳkl is the non-radiative transition probability; fi is the Korster-Kronig coefficient; σ ϳ , the ionization cross-section defined by the matrix element (1) calculated for wave functions of bound state and continuum one. In table 1 we present the data on Auger electron energy for some solids calculated using the presented approach (column C), the semi-empirical method with using the Larkins' equivalent core approximation [8] (column A), the perturbation theory approach [11,12] as well as experimental data (c.g. [1]).…”

“…where the item ∆ takes into account the dynamic correlation effects (relaxation due to hole screening with electrons etc.) To take these effects into account, the set of procedures elaborated in the atomic theory [3][4][5]11,12] is used. All calculations are performed on the basis of the modified numeral code Superatom (version 93).…”

“…In fact, a consistent Auger decay theory has to take into account correctly a number of correlation effects, including the energy dependence of the vacancy mass operator, the continuum pressure, spreading of the initial state over a set of configurations etc. [9][10][11][12][13][14][15][16][17][18][19][20]. Note that the effects are not described adequately to date, in particular within the Auger decay theory [2].…”

“…The theoretical predictions based on MCDF calculations have been carried out within different approximations and remained hitherto non-satisfactory in many relations. Earlier [11,12] it has been proposed relativistic perturbation theory (PT) method of the Auger decay characteristics for complex atoms, which is based on the Gell-Mann and Low S-matrix formalism energy approach and many-body perturbation theory (PT) formalism [4][5][6][7]. The novel element was in using the optimal basis of the electron state functions derived from the minimization condition for the calibration-non-invariant contribution (the second order PT polarization diagrams contribution) to the imaginary part of the multi-electron system energy already at the first non-disappearing approximation of the PT.…”