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Knudsen effusion mass spectrometric determination of the complex vapor composition of samarium, europium, and ytterbium bromides
Author(s) -
Sergeev D. N.,
Butman M. F.,
Motalov V. B.,
Kudin L. S.,
Krämer K. W.
Publication year - 2013
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.6617
Subject(s) - vaporization , chemistry , europium , lanthanide , analytical chemistry (journal) , mass spectrometry , electron ionization , ionization , samarium , disproportionation , ytterbium , ion , inorganic chemistry , organic chemistry , chromatography , physics , optoelectronics , doping , catalysis
RATIONALE The vaporization of Sm, Eu, and Yb tri‐ and dibromides is accompanied by decomposition and disproportionation reactions. These result in complex vapor compositions whose analysis is an intricate problem for experimentalists. Approaches have been developed to interpret mass spectra and accurately determine the vapor composition of thermally unstable compounds. METHODS A sector type magnet instrument was used. A combined ion source allowed the study of both the molecular and ionic vapor compositions in the electron ionization (EI) and the thermionic emission (TE) modes. The methodological approaches were based on a joint analysis of the ionization efficiency functions, the temperature and time dependences of the ion currents, and special mathematical data evaluation. RESULTS The vaporization of SmBr 3 , YbBr 3 , SmBr 2 , EuBr 2 , and YbBr 2 was studied in the temperature range of 850–1300 K. An initial stage of incongruent vaporization was observed in the case of the tribromides, SmBr 2 , and YbBr 2 . This eventually changed to a congruent vaporization stage. Various neutral (Ln, Br, Br 2 , LnBr, LnBr 2 , LnBr 3 , Ln 2 Br 4 , Ln 2 Br 5 , and Ln 2 Br 6 ) and charged (Br – , LnBr 3 – , LnBr 4 – ) species were detected at different vaporization stages. CONCLUSIONS The quantitative vapor composition of Sm, Eu, and Yb tri‐ and dibromides was determined. It was found that only EuBr 2 was stable in the studied temperature range. The developed approaches can be useful in the case of other thermally unstable compounds. Copyright © 2013 John Wiley & Sons, Ltd.