Simple formulas for describing the extended fine structures of spectra of electron energy losses (EELFS) with allowance for the multipolarity of the process of excitation of the inner level of atoms by electron impacts have been derived. The experimental M 2,3 EELFS spectra of nickel and K EELFS spectra of oxygen were obtained from pure samples of nickel and stoichiometric oxide film on the surface of nickel. Good agreement has been obtained between the experimental and calculated results, as well as between the parameters of a local atomic structure obtained from the experimental EELFS spectra and available crystallographic data.

Получены протяженные тонкие структуры спектров энергетических потерь электронов (EELFS) M-краев ионизационных потерь для чистой поверхности монокристаллического (110) Ni, стехиометрической сверхтонкой (1 нм) оксидной пленки NiO и сверхтонкой пленки нестехиометрической системы Ni-O. Из полученных EELFS-спектров выделены соответствующие нормированные осциллирующие части. В приближении ОПВ проведен расчет амплитуд и интенсивностей возбуждения внутреннего уровня атома вещества электронным ударом. На основе расчетных данных, в рамках решения обратной задачи по Тихонову, найдены межатомные расстояния и координационные числа.

The problem of multipolarity of the atom core level ionization by electron impact in extended energy loss fine structure (EELFS) spectroscopy is studied. The intensities and amplitudes of electron transitions have been calculated in the OPW approximation. The experimental K EELFS spectra of Al, Si and L EELFS spectra of Fe, Co have been obtained. Corresponding calculations have been carried out in the monopole and dipole approximations. A comparison of theoretical and experimental spectra have been made. It is shown that a good agreement between the theoretical and experimental results points to the need for taking account of multipolarity of the electron transition processes in EELFS calculations.

The surfaces of crystalline samples of 3d-metals (Mn, Fe, Co, Ni, and Cu) and their stoichiometric oxides have been studied by Auger spectroscopy. A correlation between the change in the LVV (L-inner level-valence-valence electron transition) Auger intensities and the change of the squares of the corresponding atomic-magnetic moments has been observed. This is because of the complicated nature of the Auger process. That is, the Auger electron emission is a result of the inner atomic level excitation by electron impact and Auger annihilation of the inner-level hole. Therefore, the Auger process has been considered a second-order process, and spin polarization of the valence states has been taken into account for the LMM (L-inner level-M-inner level-M-inner level electron transition) Auger spectra of 3d-metals.