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Glass–crystalline materials with high iron oxide concentration: Phase composition, redox ratio and magnetic properties

1 February 2024

Harizanova, R., Mihailova, I., Cherkezova-Zheleva, Z., Paneva, D., Georgieva, M., Tzankov, D., Avdeev, G., R?ssel, C.
     ( Даниела Панева; Зара Черкезова-Желева; )

Abstract

The synthesis of glass–crystalline materials in the system Na2O/CaO/SiO2/Fe2O3 with high concentrations of Fe2O3 (20, 25 and 30 mol%) by applying the melt-quenching technique is reported. The melts spontaneously crystallize during pouring and the formation of magnetite (Fe3O4), hematite (?-Fe2O3) and ?-Fe2O3, as identified by X-ray diffraction (XRD) is observed. The microstructure and the elemental composition of the prepared materials are further investigated by scanning electron microscopy (SEM) and two different morphological types of Fe-containing crystals – needle-like and dendrite-shaped are detected. M?ssbauer spectroscopy showed the presence of Fe3+ and Fe2+, as well as the existence of iron ions both in tetrahedral and octahedral coordination and the precipitation of hematite, ?-Fe2O3 and magnetite. The magnetic measurements on the prepared samples reveal ferrimagnetic properties with well defined hysteresis curves, although due to relatively small volume fraction of the iron-rich crystalline phases, the net magnetic moment is quite low compared to the bulk values for magnetite.

Boletin de la Sociedad Espanola de Ceramica y Vidrio, 63, 1, Sociedad Espanola de Ceramica y Vidrio, 2024, ISSN:03663175, DOI:10.1016/j.bsecv.2023.04.001, 23-32. SJR (Scopus):0.47 Q1, не оглавява ранглистата (Web of Science)

https://www.sciencedirect.com/science/article/pii/S0366317523000183?via%3Dihub


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