Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by MOOKHERJEE, M. Articles by REDFERN, S. A. T. Search for Related Content GeoRef GeoRef Citation

A high-temperature Fourier transform infrared study of the interlayer and Si–O-stretching region in phengite-2M₁

¹ Department of Earth Sciences, University of Cambridge, Downing St., Cambridge CB2 3EQ, UK, and ² R.S.E.S, Australian National University, Mills Road, Canberra ACT 0200, Australia

^* E-mail: mm329{at}cam.ac.uk

(Received 22 June 2001; revised 10 October 2001)

A natural phengite-2M₁ of composition (K_0.95Na_0.05)(Al_0.76Fe_0.14Mg_0.10)₂ (Si_3.25Al_0.75)O₁₀(OH_1.96F_0.04) [a = 5.2173(1) Å, b = 9.0493(2) Å, c = 19.989 (1) Å and ß = 95.734(4)°] was studied using in situ high-temperature FTIR. Correlations to structural changes were made using previously-reported neutron diffraction data from the same sample. Correlations have been made between the microscopic atomic displacements (arising from thermal effects) and analogous macroscopic properties, such as bond strain and ditrigonal distortions. Spectra were collected in the far-infrared region to study the behaviour of the interlayer (K⁺) cation and also in the mid-infrared region to distinguish the Si–O stretching modes. We found anisotropic thermal expansion of the interlayer site. The K–O bond length is divided into K–O_outer and K–O_inner, and the K–O_inner bond length is correlated with the far-infrared spectra. The thermal dependence of the correlation between K–O bond length and corresponding far-infrared stretching frequency is different from the effect of the chemical composition. We also found that the K–O bond strain could be successfully resolved into the sum of inner strain and lattice strain. The Si–O stretching mode, obtained from the mid-infrared measurements, showed only weak changes. However, the neutron refinement data showed different thermal behaviour for distinct crystallographic T-sites.

KEYWORDS: phengite-2M₁, FTIR, lattice and inner deformation

This article has been cited by other articles:

				G. Ventruti, M. Zema, F. Scordari, and G. Pedrazzi Thermal behavior of a Ti-rich phlogopite from Mt. Vulture (Potenza, Italy): An in situ X-ray single-crystal diffraction study American Mineralogist, April 1, 2008; 93(4): 632 - 643. [Abstract] [Full Text] [PDF]

				O. Klein-BenDavid, R. Wirth, and O. Navon TEM imaging and analysis of microinclusions in diamonds: A close look at diamond-growing fluids American Mineralogist, February 1, 2006; 91(2-3): 353 - 365. [Abstract] [Full Text] [PDF]

				C.-M. Chon, C.-M. Chon, S. A. Kim, and H.-S. Moon CRYSTAL STRUCTURES OF BIOTITE AT HIGH TEMPERATURES AND OF HEAT-TREATED BIOTITE USING NEUTRON POWDER DIFFRACTION Clays and Clay Minerals, October 1, 2003; 51(5): 519 - 528. [Abstract] [Full Text] [PDF]