Experimental study of atomic 4dgiant resonances by photoabsorption and photoelectron spectroscopy: Ba, La, and Ce

Abstract

Total and partial (4d ', 4f ', 5s ', 5p ', Sd ', 6s ') cross sections of atomic Ba, La, and Ce have been determined by absorption and photoelectron spectroscopy in the range of the giant 4d~(4f, ef) resonances. Many electron theories that take polarization and relaxation effects into account describe the gross features of the spectra but in many cases fail to reproduce the exact energy positions, line shapes, and amplitudes of the resonances in the cross sections of the main and satellite lines.

Analysis of 4f Level in Samarium-Rich MBE Grown CdSmTe Sample

“…The splitting of 4f -1 final states equal to 2.9 eV and the splitting of 5p -1 final states equal to 5.4 eV are comparable with splitting of final states of Sm atomic sample [2] (2.7 eV and 6.1 eV respectively). Taking into account these properties and localised character of f shell, one can assign the structures mentioned above to the following transition basing on the results for atomic samarium [2]. The structure marked as α is assigned to the Sm 4f66s2 7F -4f5 6s2 6Η 6F, while marked by b is caused by the Sm 4f66s2 7F -> 4f5 6s2 6Ρ transition.…”

“…2) show the maximum value obtained for 143.3 eV. The CIS spectra possess rich structure character well corresponding to the rich structure of absorption spectra of Sm 4f electrons [2]. The interpretation of the obtained results needs application of highly advanced theory as the Sm 4f orbital possesses localised character with the strongly correlated electrons.…”

“…The structure marked by c is attributed to the final state 5p3 /2 4f6 6s2 while marked by d to the 5pi /24f6 6s2 . It should be mentioned that the binding energy of the above peaks is shifted to the smaller binding energy in comparison with data for atomic samarium [2] but in comparison with the result for SmTe these values of binding energies are shifted to higher energies [3]. Figure 2 shows the spectra obtained by CIS technique.…”

Valence-Band Dispersion in Angle-Resolved Resonant Photoemission from LaSb

“…This is supported by a theoretical study by Zangwill and co-workers [3,6], who calculated the cross sections for the emission of photoelectrons from various subshells, e.g., 4f, 5d, 6s, after photoexcitation of a 4d electron of the Ce atom. Subsequently these cross sections were measured in Ce and La vapor by Meyer and co-workers [19,20] with good, but not perfect, agreement. Zangwill found that as one scanned through the 4d photoexcitation from low photon energy to high, the subshell emission resonances peaked at increasing energies as the average radius of the subshell electrons decreased.…”

The Ba 4d–4f giant dipole resonance in complex Ba/Si compounds

“…These collective excitations can be observed as universal features in nuclei, atoms, clusters, and solids. Although giant dipole resonances (GRs) in atoms and condensed matter have been studied intensively, [3,4,5,6] they have attracted a renewed interest in recent years. [7,8,9,10,11,12,13] Owing to the availability of highly intense synchrotron radiation and advanced experimental setups, new materials can be studied in which resonating atoms are embedded into fascinating complex environments like endohedral fullerenes or silicon based clathrates.…”