D. V. Surnin

Electron-impact excitation of internal atomic layers of a substance in the formation of extended fine structures of electron emission spectra

The formalism of collision theory was used to describe the formation of extended electron energy loss fine structures taking into account multipolarity of the electron-impact excitation of internal atomic layers, and the formation of extended secondary electron fine structures taking into account the first and second order nonradiative relaxation of excited state of the electronic subsystem of a sample. The extended electron energy loss fine structures, extended secondary electron fine structures, and corresponding oscillating parts were obtained in the experiments. The experimental and calculated data showed good agreement.

Allowance for the background component in X-ray photoelectron and Auger electron spectroscopy

A simple and efficient method of subtraction of the nonlinear background in X-ray diffraction and Auger electron spectroscopy is suggested. The method has been verified using test samples of Fe-Ni alloys and oxides of transition metals of a known composition.

Analysis of the local atomic structure of manganese and its oxides by extended energy loss fine structure spectroscopy

A technique for determining parameters of the local atomic structure of a manganese-oxygen system by the extended energy loss fine structure method has been proposed. Experimental extended energy loss fine structure spectra of the clean surface of metallic manganese and its stoichiometric oxides have been measured. Normalized oscillating portions have been separated from the experimental spectra and analyzed by solving the inverse problem using the Tikhonov regularization. The parameters of the local atomic structure of the objects under study, i.e., coordination numbers, bond lengths, and their variance parameters, have been determined.

Characterization of thin carbon films formed on the iron surface by magnetron sputtering with ion-beam mixing

The chemical composition, interatomic chemical bonds, and specific features of the atomic structure of nanosized carbon films on the surface of iron, which were prepared by magnetron sputtering before and after ion-beam mixing, have been investigated using X-ray photoelectron spectroscopy, X-ray diffraction analysis, extended electron energy loss fine structure spectroscopy, and Raman spectroscopy. It has been found that, in the ion-beam mixing region, there are structural inhomogeneities and nonstoichiometric iron carbides. The parameters of the local atomic structure of an ultrathin surface layer and the “carbon film–metal” transition region have been determined.

Chemical composition and atomic structure of the surface of copper–manganese alloy modified with oxygen ions

The regularities of the formation of the chemical composition of thin surface layers of Cu–Mn alloy under irradiation with oxygen ions in the pulse-periodic mode with different parameters of exposure are investigated by X-ray photoelectron spectroscopy (XPS). We study the distribution patterns and chemical state of the alloy elements in the ion-implanted layers, depending on the dose and energy of irradiation. It is found that with increasing irradiation dose, the alloy components are redistributed in the surface layers, and increasing ion energy leads to decomposition of the initial solid solution.

The role of auto-ionization transitions in the formation of the extended fine structure of high-energy secondary electron spectra

Extended fine structure (EFS) of secondary electron (SE) spectra has been detected beyond the high-energy (∼720 and ∼840 eV) LVV Auger lines in iron and nickel. Two mechanisms of its formation are considered: 1) direct transitions of electrons to the final state p according to Fermi’s “golden rule” and 2) second-order processes of auto-ionization type, passing through excitation of a core electron to an intermediate state q of the continuum with subsequent filling of the hole formed during this process by a valence electron and transition of the electron from the intermediate state q to the final state p. Interference of the direct wave with the wave reflected from neighboring atoms generates the EFS both in the final (p) and in the intermediate (q) state with two different periods determined by the wave numbers p and q. Comparison of calculated extended fine structures with the experimentally observed ones leads to the conclusion that the structure is formed by second-order auto-ionization processes.