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Fine structure of the extreme ultraviolet spectra of the potassium halide crystals at 10 °K
Author(s) -
Blechschmidt D.,
Haensel R.,
Koch E. E.,
Nielsen U.,
Skibowski M.
Publication year - 1971
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2220440238
Subject(s) - spectral line , exciton , synchrotron radiation , halide , valence (chemistry) , conduction band , atomic physics , chemistry , photon energy , reflection (computer programming) , photon , condensed matter physics , optics , physics , electron , inorganic chemistry , organic chemistry , astronomy , quantum mechanics , computer science , programming language
The reflection spectra of KCl, KBr, and KI single crystals and of a KF film have been measured below 10 °K for photon energies between 10 and 30 eV using synchrotron radiation. The numerous new spectral features at low temperature are discussed in terms of electronic transitions from the valence band and from the K + 3p level. Due to spin‐orbit interaction of the K + 3p level the Γ‐K + 3p core exciton at about 20 eV is split into two lines with an energy separation of about 0.2 eV for all halides. The observed fine structure and a comparison with a calculated conduction band density of states in the case of KI support the excitonic nature of the Γ‐X K + 3p doublet.