On the local coordination of Fe in Fe2O3-glass and Fe2O3-glass ceramic systems containing Pb, Na and Si

X-ray absorption spectroscopies: A novel tool for the nanostructural characterization of stabilized industrial waste

“…2(a)). The former distance is characteristic of octahedral (0.196-0.203 nm) coordination of Fe [14] while the latter for tetrahedral (0.1865 nm) [4,12,15]. Therefore, it is proposed that in the glassy matrix of the samples, the Fe atoms occupy both octahedral and tetrahedral sites.…”

“…1(a) and (b), in the FTs of the spectra at both the Fe-and Zn-K edges, only one peak is resolved, which corresponds to the 1st nearest neighbor (nn) shell. The absence of structure at distances higher than the 1st nn shell indicates that the samples are amorphous [12,13]. Therefore, the fitting of the Fe-and Zn-K-EXAFS spectra was performed using one shell which comprises of O atoms.…”

“…The fitting was performed simultaneously for all samples, i.e. the value of the Debye-Waller factor was iterated for only one sample while it was kept fixed in the rest of the samples [12,13]. The fitting parameters were the coordination numbers of Fe and Zn (N(O)) and the Fe-O (R Fe-O ) and Zn-O bondlengths (R Zn-O ), at the Fe-and Zn-K edges, respectively.…”

Effect of Oxidation State of Iron Ions on the Viscosity of Alkali Silicate Melts

“…[1][2][3][4][5][6][7][8] In particular, the oxidation states of the iron ions in metallurgical slags can easily change depending on the conditions of the processes in which the slags are employed. 9) In addition, FeO (Fe 2+ ) is known to form octahedra (Fe 2+ (6)) and behaves as a network modifier, 10) while Fe2O3 (Fe 3+ ) plays an intermediate role between the network former and the network modifier 10,11) since it forms both tetrahedra (Fe 3+ (4)) and octahedra (Fe 3+ (6)). Therefore, the ratio of the Fe 2+ content to the total amount of Fe (Fe 2+ /totalFe) in the melts should affect the viscosity.…”

Micro‐structural characterization of red decorations of red and green color porcelain (Honglvcai) in China

“…It could be observed that the intensities of the preedge peaks of red decorations were stronger than that of Fe 2 O 3 crystalline powder, which reflected the increased number of unoccupied O 2p states available for mixing with the Fe 3d states [30] and indicated that iron in red decorations might occupy a higher distorted octahedral sites. [31,32] According to the density of electron states of antiferromagnetic α-Fe 2 O 3 , the upper valence band, lying just below the Fermi energy (E F ), was essentially of 2p(O) states with a minor presence of 3d (Fe) states. A conduction band of 3d (Fe) character, with a small contribution from 2p(O) levels, was finally observed above E F .…”