A multi-analytical approach for the analysis of cation distribution in a aluminoceladonite structure

Authors

  • Mariola Kądziołka-Gaweł Institute of Physics, University of Silesia, 75 Pułku Piechoty 1, 41-500 Chorzów
  • Mateusz Dulski Institute of Material Science, University of Silesia, 75 Pułku Piechoty 1a, 41-500 Chorzów
  • Maria Czaja Faculty of Earth Sciences, University of Silesia, Będzińska 60, 41-200 Sosnowiec
  • Tomasz Krzykawski Faculty of Earth Sciences, University of Silesia, Będzińska 60, 41-200 Sosnowiec
  • Magdalena Szubka Institute of Physics, University of Silesia, 75 Pułku Piechoty 1, 41-500 Chorzów

Keywords:

Aluminoceladonite, Ions position characterization isomorphic substitutions, Fe‑bearing phyllosilicates, X-ray photoelectron spectroscopy, Mössbauer spectroscopy, Raman spectroscopy

Abstract

In this paper cation arrangement in two samples of aluminoceladonite, emerald‑green and dark-green were studied by Mössbauer, Raman and X-ray photoelectron spectroscopies. The X-ray photoelectron spectroscopy (XPS) spectra obtained in the region of the Si2p, Al2p, Fe2p, K2p, and O1s core levels provided information, for the first time highlighting a route to identify the position of Si, Al, K, and Fe cations in a structure of layered silicates. The XPS analysis showed the presence of Al in tetrahedral and octahedral coordination while the K2p line indicated the possibility of K+ substitution by other cations in interlayer sites. Mössbauer spectroscopy provided information about crystal chemistry with respect to the local electronic and geometric environment around the Fe atom and to distortions of the polyhedra. It turned out that iron was located mostly in the cis-octahedra position wherein about 75% of iron appeared in the form of Fe3+. The most preferred cation combinations around Fe corresponded to 3Fe3+ ions and MgFe2+Fe3+/2MgFe3+. Raman spectroscopy illustrated aluminium substitution in silicon and iron positions wherein the concentration of the aluminium determined the degree of structural distortion within the layered system. These isomorphic substitutions implied a typical band arrangement in the hydroxyl region, which has not been observed in celadonites so far.

Downloads

Published

2022-09-19

Issue

Section

Articles