Record details

Title
    Effects of chemical composition and temperature of heating on the infrared spectra of Li-saturated dioctahedral smectites. II, Near-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. 753-761
Year
    2000
Notes
    7 obr., 1 tab., 11 bibl.
    il.
    Lokality vzorků (LOC) totožné jako v části (I) - viz. s. 754
    Zkr. název ser.: Clay Miner.
Subject group
    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
    II
    Infrared
    Li-saturated
    Near-infrared
    Region
    Smectites
    Spectra
    Temperature
Abstract (in english)
   Diffuse reflectance spectra in the near-infrared region are presented for Li-saturated smectites heated up to 200°C. The smectites included three montmorillonites an Fe-beidellite and a ferruginous smectite. Unheated samples showed a complex band near 4060 cm-1 assigned to the first overtone of the OH-stretching mode of structural hydroxyl groups and bound H2O. The OH combination bands appeared in the 4600-4300 cm-1 region. Spectra of heated montmorillonites showed an upward shift and splitting of the OH-overtone band into two component near 7170 and 7110 cm-1. The presence of a band near 7170 cm-1, assigned to the overtone of the AlMgLiOH-stretching vibration, implied that local trioctahedral domains were created upon Li(I) fixation in the previously vacant octahedral positions of montmorillonites. The OH combination bands were shifted to higher frequencies and a new band appeard near 4472 cm-1 in the spectra of montmorillonites heated to temperatures in excess of 130°C.
   No features indicating Li(I) in the structure of Fe-beidellite of ferruginous smectite were observed in the NIR spectra
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    18. 7. 2007
Import date
    8. 8. 2012