Crystal structure and iron topochemistry of erionite-K from Rome, Oregon, U.S.A.

Ballirano P., Andreozzi G. B., Dogan M., DOĞAN A.

American Mineralogist, cilt.94, sa.8-9, ss.1262-1270, 2009 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 94 Sayı: 8-9
  • Basım Tarihi: 2009
  • Doi Numarası: 10.2138/am.2009.3163
  • Dergi Adı: American Mineralogist
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1262-1270
  • Anahtar Kelimeler: Crystal structure, Erionite-K, Field emission, Iron topochemistry, Laboratory parallel-beam transmission powder diffraction, Oregon erionite, Rietveld refinement, Scanning electron microscopy
  • Ankara Üniversitesi Adresli: Hayır

Özet

A complete crystal-chemical characterization of erionite-K from Rome, Oregon, was obtained by combining field emission scanning electron microscopy, laboratory parallel-beam transmission powder diffraction, and 57Fe Mössbauer spectroscopy. Rietveld refinement results evidenced that the most striking difference in comparison with the structure of erionite-Ca is significant K at a K2 site (1/2, 0, 0), which is empty in erionite-Ca. In addition, site Ca1 shows low occupancy and Ca3 is vacant. The oxidation and coordination state of Fe, whose occurrence was revealed by chemical analysis, have been clarified by exploiting room- and low-temperature 57Fe Mössbauer spectroscopy. The majority of Fe (95%) was attributed to Fe 3+-bearing, superparamagnetic, oxide-like nanoparticles with dimensions between 1 and 9 nm, and the remaining 5% was attributed to hematite particles with size >10 nm, both located on the crystal surface.