Open AccessA preliminary investigation of chlorine XANES in silicate glasses
Author(s) -
Evans K. A.,
Mavrogenes J. A.,
O'Neill H. S.,
Keller N. S.,
Jang L.Y.
Publication year - 2008
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2008gc002157
Subject(s) - xanes , silicate , ionic bonding , stoichiometry , absorption (acoustics) , spectral line , genetic algorithm , inorganic chemistry , ion , mineralogy , analytical chemistry (journal) , geology , chemistry , materials science , environmental chemistry , physics , astronomy , biology , organic chemistry , evolutionary biology , composite material
Chlorine speciation in silicate melts affects volatile exsolution, rheology, and thermodynamic properties of the melt but is poorly known. X‐Ray Absorption Near Edge Structure (XANES) spectra have been used to investigate Cl speciation in 26 silicate glasses and to test the hypothesis that Cl in silicate melts is hosted by species that combine Cl and network‐modifying cations such as Ca and Mg. Results indicate that Cl in CMAS (CaO‐MgO‐Al 2 O 3 ‐SiO 2 ) plus Na 2 O, K 2 O, or MnO silicate glasses exists as a combination of Ca‐Cl x and Mg‐Cl x species or, possibly, as mixed Ca‐Mg y ‐Cl x species. The geometry and stoichiometry of the proposed species is unknown, but there are similarities between spectra from Ca‐bearing melts and the spectra of hydrated CaCl 2 .2H 2 O, suggesting that the Ca‐Cl x species could have a salt‐like atomic arrangement and ionic bonding. Further investigations using XANES, alternative spectroscopic techniques, and forward modeling approaches are required to distinguish between these possibilities.