http://hdl.handle.net/20.500.12128/6201
Tytuł: | Dynamic disorder of Fe3+ ions in the crystal structure of natural barioferrite |
Autor: | Krzątała, Arkadiusz Panikorovskii, Taras L. Galuskina, Irina Galuskin, Evgeny |
Słowa kluczowe: | Barioferrite; Crystal structure; Hatrurim complex; Raman; Single-crystal investigation |
Data wydania: | 2018 |
Źródło: | Minerals, Vol. 8, iss. 8 (2018), Art. no. 340 |
Abstrakt: | A natural barioferrite, BaFe3+ 12O19, from a larnite–schorlomite–gehlenite vein of paralava within gehlenite hornfels of the Hatrurim Complex at Har Parsa, Negev Desert, Israel, was investigated by Raman spectroscopy, electron probe microanalysis, and single-crystal X-ray analyses acquired over the temperature range of 100–400 K. The crystals are up to 0.3 mm × 0.1 mm in size and form intergrowths with hematite, magnesioferrite, khesinite, and harmunite. The empirical formula of the barioferrite investigated is as follows: (Ba0.85 Ca0.12 Sr0.03)∑1 (Fe3+ 10.72Al0.46 Ti4+ 0.41Mg0.15 Cu2+ 0.09Ca0.08 Zn0.04 Mn2+ 0.03Si0.01)∑11.99 O19. The strongest bands in the Raman spectrum are as follows: 712, 682, 617, 515, 406, and 328 cm−1. The structure of natural barioferrite (P63 /mmc, a = 5.8901(2) Å, c = 23.1235(6) Å, V = 694.75(4) Å3, Z = 2) is identical with the structure of synthetic barium ferrite and can be described as an interstratification of two fundamental blocks: spinel-like S-modules with a cubic stacking sequence and R-modules that have hexagonal stacking. The displacement ellipsoids of the trigonal bipyramidal site show elongation along the [001] direction during heating. As a function of temperature, the mean apical Fe–O bond lengths increase, whereas the equatorial bond lengths decrease, which indicates dynamic disorder at the Fe2 site. |
URI: | http://hdl.handle.net/20.500.12128/6201 |
DOI: | 10.3390/min8080340 |
ISSN: | 2075-163X |
Pojawia się w kolekcji: | Artykuły (WNP) |
Plik | Opis | Rozmiar | Format | |
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Krzatala_Dynamic_disorder_of_Fe3+.pdf | 3,44 MB | Adobe PDF | Przejrzyj / Otwórz |
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