Record details

Title
    Effects of chemical composition and temperature of heating on the infrared spectra of Li-saturated dioctahedral smectites. I, Mid-infrared region
Statement of responsibility
    J. Madejová, J. Bujdák, S. Petit, P. Komadel
Author
    Bujdák, J.
    Komadel, P.
    Madejová, J.
    Petit, S.
Language
    anglicky
Source title - serial
    Clay minerals
Vol./nr.
    Vol. 35, no. 5
Pages
    p. 739-751
Year
    2000
Notes
    10 obr., 1 tab., 2 s.bibl.
    il.
    Zkr. název ser.: Clay Miner.
Subject group
    iontová výměna
    krystalochemie
    lithium
    montmorillonit
    smektity
    spektrometrie IR
    teplota
Geographical name
    Česká republika
    Horní Dunajovice (Znojmo)
    Stebno (Ústí nad Labem)
    USA
Keyword
    Chemical
    Composition
    Dioctahedral
    Effects
    Heating
    Infrared
    Li-saturated
    Mid-infrared
    Region
    Smectites
    Spectra
    Temperature
Abstract (in english)
   Infrared spectroscopy in the mid-IR region was used to follow the structural changes occurring in five Li-saturated dioctahedral smectites upon heating. The smectites included three montmorillonites, an Fe-beidellite and a ferruginous smectite. Fixation of Li+ ions in the structure even upon heating at 120°C caused the appearance of an AlMgLiOH-stretching band near 3670 cm-1 in the spectra of all three montmorillonites. This band confirmed the presence of Li(I) in the previously vacant octahedral positions in montmorillonites. No similar band was observed in the spectra of ferruginous heated smectites with prevailing tetrahedral charge. A gradual upward frequency shift and decrease in intensity of the AlAlOH-bending band showed that Li(I) present in the hexagonal cavities causes pronounced perturbation of this OH-bending mode. The Li(I) present in the octahedral sheets causes small perturbations of the OH-bending mode near 850 cm-1 and activation of a new OH-bending mode near 803 cm-1.
   
   Reversible changes in the positions of the stretching Si-O and bending OH bands in the spectra of Fe-beidellite and a ferruginous smectite proved that Li was present in these minerals primarily in the hexagonal holes of the tetrahedral sheets
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    18. 7. 2007
Import date
    8. 8. 2012