Terahertz time-domain spectroscopy of selected layered silicates
Janek, Marián (Comenius University. Department of Physical and Theoretical Chemistry)
Bugár, Ignác (International Laser Centre)
Lorenc, Dusan (TU Vienna. Institut für Photonik)
Szöcs, Vojtech (Comenius University. Institute of Chemistry)
Velic, Dusan (International Laser Centre)
Chorvát, Dusan (International Laser Centre)

Data:	2009
Resum:	Micaceous layer silicate clay minerals are attractive materials for applications involving non-linear optics because of their low cost and ability to form well ordered, platy aggregates, but such applications require precise knowledge of the dielectric behavior of the clay. The purpose of the present study was to use Terahertz time-domain spectroscopy (THz-TDS) to determine the dielectric properties of certain cleavable layered clay minerals, including muscovite, vermiculite, phlogopite, and biotite. The samples were characterized by X-ray diffraction and Fourier transform infrared spectroscopy as well as chemical analysis by Energy dispersive X-ray spectroscopy. The THz frequency window investigated was the far-infrared region of 3. 3 to ~40. 0 cm corresponding to 0. 1 and 1. 2 THz, respectively. The samples were selected so that the hydrated form of the interlayer cation, e. g. Mg present in the interlayer gallery of vermiculite, could be compared to species such as phlogopite, biotite, and muscovite with the dehydrated form of interlayer cations such as K or Na. The frequency-dependent complex index of refraction of these natural materials was determined to vary between 2. 50 and 2. 80. The presence of water in the interlayer space of vermiculite was reflected in the detection of increased values of the absorption index in comparison with the muscovite, phlogopite, and biotite.
Drets:	Aquest material està protegit per drets d'autor i/o drets afins. Podeu utilitzar aquest material en funció del que permet la legislació de drets d'autor i drets afins d'aplicació al vostre cas. Per a d'altres usos heu d'obtenir permís del(s) titular(s) de drets.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Matèria:	Absorption Index ; Biotite ; Far-infrared ; Index of Refraction ; Layered Silicates ; Muscovite ; Phlogopite ; THz-TDS ; Vermiculite
Publicat a:	Clays and Clay Minerals, Vol. 57, Núm. 4 (2009) , p. 416-424, ISSN 1552-8367

DOI: 10.1346/CCMN.2009.0570402

9 p, 539.6 KB  Accés restringit a la UAB

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