Ion exchange and fixation of rare-earth cation into expandable tetrasilicic fluorine mica

Rare‐earth cation (Nd3+) are incorporated into the interlayer spaces between the silicate layers of synthetic fluorine mica, Na0.665Mg2.68(Si3.98Al0.02)O10.02F1.98, by conventional ion exchange reaction. Subsequent migration of the interlayer cations upon calcination into the vacant octahedra of 2:1...

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Bibliographic Details
Published in:Journal of synchrotron radiation 2001-03, Vol.8 (2), p.731-733
Main Authors: Han, Yang-Su, Choi, Shin-Hei, Kim, Dong-Kuk
Format: Article
Language:English
Subjects:
Cation exchanging
Fixation
Fluorine
Mica
Rare earth metals
Synchrotron radiation
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Summary:Rare‐earth cation (Nd3+) are incorporated into the interlayer spaces between the silicate layers of synthetic fluorine mica, Na0.665Mg2.68(Si3.98Al0.02)O10.02F1.98, by conventional ion exchange reaction. Subsequent migration of the interlayer cations upon calcination into the vacant octahedra of 2:1 layers is followed by powder X‐ray diffraction, diffuse‐reflectance UV spectroscopy, and X‐ray absorption spectroscopy as a function of calcination temperature. It is found from the spectroscopic analyses that the interlayer cations start to migrate into the octahedral vacant sites from 400°C through the hexagonal siloxane ring of the tetrahedral silicate layers. According to the Nd LIII‐edge XANES spectra, the normalized absorption intensity gradually decreases while the FWHM increases with temperature, suggesting that the bonding character of rare‐earth cations and silicate lattices evolves from ionic to covalent as the calcination temperature increases.
ISSN:1600-5775
0909-0495
1600-5775
DOI:10.1107/S0909049501000188