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Title: Crystal structures of potassium-exchanged forms of catapleiite and hilairite

Abstract

The crystal structures of potassium-exchanged forms of catapleiite and hilairite of the compositions (K{sub 0.49}Ca{sub 0.42}Na{sub 0.26})ZrSi{sub 3}O{sub 9} . 2[(H{sub 2}O){sub 0.8}(H{sub 3}O){sub 0.2}] and K{sub 0.51}ZrSi{sub 3}O{sub 9} . 3[(H{sub 2}O){sub 0.5}K{sub 0.27}(H{sub 3}O){sub 0.23}], respectively, were studied by X-ray diffraction and IR spectroscopy. Both structures retain the heteropolyhedral frameworks of the parent minerals formed by Zr octahedra and Si tetrahedra. The K cations occupy different positions in these minerals. In K-exchanged catapleiite, K cations are located only in the position occupied by Na in the structure of the parent mineral. In the K-exchanged form of hilairite, K cations are not only involved in the Na position but also partially occupy the H{sub 2}O position.

Authors:
; ; ;  [1]; ;  [2];  [3]
  1. Moscow State University, Faculty of Geology (Russian Federation)
  2. University of Pisa, Department of Earth Sciences (Italy)
  3. Russian Academy of Sciences, Institute of Problems of Chemical Physics (Russian Federation)
Publication Date:
OSTI Identifier:
21091393
Resource Type:
Journal Article
Resource Relation:
Journal Name: Crystallography Reports; Journal Volume: 52; Journal Issue: 1; Other Information: DOI: 10.1134/S1063774507010075; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CALCIUM COMPOUNDS; CATIONS; CRYSTAL STRUCTURE; INFRARED SPECTRA; MINERALS; OXIDES; POTASSIUM COMPOUNDS; SODIUM COMPOUNDS; X-RAY DIFFRACTION; ZIRCONIUM COMPOUNDS

Citation Formats

Zubkova, N. V., E-mail: dmitp@geol.msu.ru, Pekov, I. V., Turchkova, A. G., Pushcharovskii, D. Yu., Merlino, S., Pasero, M., and Chukanov, N. V. Crystal structures of potassium-exchanged forms of catapleiite and hilairite. United States: N. p., 2007. Web. doi:10.1134/S1063774507010075.
Zubkova, N. V., E-mail: dmitp@geol.msu.ru, Pekov, I. V., Turchkova, A. G., Pushcharovskii, D. Yu., Merlino, S., Pasero, M., & Chukanov, N. V. Crystal structures of potassium-exchanged forms of catapleiite and hilairite. United States. doi:10.1134/S1063774507010075.
Zubkova, N. V., E-mail: dmitp@geol.msu.ru, Pekov, I. V., Turchkova, A. G., Pushcharovskii, D. Yu., Merlino, S., Pasero, M., and Chukanov, N. V. Thu . "Crystal structures of potassium-exchanged forms of catapleiite and hilairite". United States. doi:10.1134/S1063774507010075.
@article{osti_21091393,
title = {Crystal structures of potassium-exchanged forms of catapleiite and hilairite},
author = {Zubkova, N. V., E-mail: dmitp@geol.msu.ru and Pekov, I. V. and Turchkova, A. G. and Pushcharovskii, D. Yu. and Merlino, S. and Pasero, M. and Chukanov, N. V.},
abstractNote = {The crystal structures of potassium-exchanged forms of catapleiite and hilairite of the compositions (K{sub 0.49}Ca{sub 0.42}Na{sub 0.26})ZrSi{sub 3}O{sub 9} . 2[(H{sub 2}O){sub 0.8}(H{sub 3}O){sub 0.2}] and K{sub 0.51}ZrSi{sub 3}O{sub 9} . 3[(H{sub 2}O){sub 0.5}K{sub 0.27}(H{sub 3}O){sub 0.23}], respectively, were studied by X-ray diffraction and IR spectroscopy. Both structures retain the heteropolyhedral frameworks of the parent minerals formed by Zr octahedra and Si tetrahedra. The K cations occupy different positions in these minerals. In K-exchanged catapleiite, K cations are located only in the position occupied by Na in the structure of the parent mineral. In the K-exchanged form of hilairite, K cations are not only involved in the Na position but also partially occupy the H{sub 2}O position.},
doi = {10.1134/S1063774507010075},
journal = {Crystallography Reports},
number = 1,
volume = 52,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}
  • Detailed structural analyses based on electron microprobe and X-ray diffraction data did not provide evidence for zero-coordinated potassium, but showed that all cations lie adjacent to framework oxygen atoms, with 2 to 6 oxygen neighbors within 3 A.
  • Elpidite Na{sub 2}ZrSi{sub 6}O{sub 15} {center_dot} 3H{sub 2}O [space group Pbcm, a = 7.1312(12), b = 14.6853(12), and c = 14.6349(15) Angstrom-Sign ] from Khan Bogdo (Mongolia) and its K- and Rb-exchanged forms K{sub 1.78}Na{sub 0.16}H{sub 0.06}ZrSi{sub 6}O{sub 15} {center_dot} 0.85H{sub 2}O [Cmce, a = 14.054(3), b = 14.308(3), and c = 14.553(3) Angstrom-Sign ] and Na{sub 1.58}Rb{sub 0.2}H{sub 0.22}ZrSi{sub 6}O{sub 15} {center_dot} 2.69H{sub 2}O [Pbcm, a = 7.1280(10), b = 14.644(3), and c = 14.642(3) Angstrom-Sign ] that were obtained by cation exchange at 90 Degree-Sign C, as well as K{sub 1.84}Na{sub 0.11}H{sub 0.05}ZrSi{sub 6}O{sub 15} {center_dot} 0.91H{sub 2}Omore » [Cmce, a = 14.037(3), b = 14.226(3), and c = 14.552(3) Angstrom-Sign ] and Rb{sub 1.78}Na{sub 0.06}H{sub 0.16}ZrSi{sub 6}O{sub 15} {center_dot} 0.90H{sub 2}O [Cmce, a = 14.2999(12), b = 14.4408(15), and c = 14.7690(12) Angstrom-Sign ], obtained at 150 Degree-Sign C are studied by single-crystal X-ray diffraction and IR spectroscopy. The base of the structures is a heteropolyhedral Zr-Si-O framework whose cavities accommodate Na (K, Rb) cations and H{sub 2}O molecules.« less
  • The crystal structures of natural and Cs-exchanged silica-rich clinoptilolite have been refined in space group C2/m using single-crystal X-ray diffraction data (R = 0.062 and 0.083, respectively; all reflections). Chemical formulae of the two structures are Na{sub 1.3}K{sub 1.2}Ca{sub 1.55}Al{sub 6.2}Si{sub 29.8}O{sub 72}{center_dot}23H{sub 2}O and Cs{sub 3.8}Ca{sub 1.2}Al{sub 6.1}Si{sub 29.7}O{sub 72}{center_dot}19H{sub 2}O. Unit-cell dimensions of the two are virtually identical (a = 17.633 {angstrom}, b = 17.941 {angstrom}, c = 7.400 {angstrom}, and {beta} = 116.39{degree} for the natural sample, and a = 17.692 {angstrom}, b = 17.945 {angstrom}, c = 7.404 {angstrom}, and {beta} = 116.36{degree} for the Cs-exchangedmore » sample). The positions of extra-framework cations in the natural sample are similar to those reported previously, except that there is no atom at the position ascribed to Mg, consistent with the low Mg content of the sample. Cs occupies split positions near high-symmetry special positions that are unrelated to the cation positions in the natural sample. All Cs positions have relatively long Cs-H{sub 2}O and Cs-O distances ranging from 3.0 to 3.5 {angstrom}. Clinoptilolite is a major component in tuffs at the Nevada Test Site, a large reservation in southern Nevada used for underground testing of nuclear weapons, and it may be used for future isolation of high-level radioactive wastes.« less
  • A perspective view of the polyhedral representation in Sr exchanged titanosilicate with sitinakite topology. The eight ring tunnel along c-axis depicts a nine coordinated Sr complex. Dark and light gray spheres in the eight ring channel represent water molecules and Sr{sup 2+} cations respectively.