Naslov
The influence of thermal treatment on the phase development of ZrO2-NiO precursors

Autori
Štefanić, Goran ; Didović, Mirna ; Musić, Svetozar

Izvornik
Journal of Molecular Structure (0022-2860) 834-836 (2007), Special Issue SI; 435-444

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
ZrO2-NiO; XRD; Raman spectroscopy; FE-SEM; FT-IR spectroscopy; DTA

Sažetak
Structural and microstructural changes during thermal treatment of the amorphous precursors of the ZrO2-NiO system were examined by differential thermal analysis, X-ray powder diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and energy dispersive X-ray spectrometry. The amorphous precursors of the ZrO2-NiO system on the ZrO2-rich side of the concentration range were prepared by co-precipitation from aqueous solutions of the corresponding salts. The crystallization temperature of the amorphous precursors increased with an increase in the NiO content, from 405 °C (0 mol% NiO) to 600 °C (30 mol% NiO). The results of phase analysis indicated that maximum solubility of Ni2+ ions in the ZrO2 lattice (not, vert, similar5 mol%) occurred in the metastable products obtained after crystallization of the amorphous precursors. The results of Raman spectroscopy indicate that the incorporation of Ni2+ ions causes partial stabilization of the tetragonal polymorph of ZrO2, but could not stabilize the cubic ZrO2. A precise determination of unit-cell parameters using the whole-powder-pattern refinements shows that the unit-cell parameters of the tetragonal (t-)ZrO2-type solid solution decrease with an increase in Ni2+ ions up to not, vert, similar5 mol%. Further increase in the nickel content has no influence on the lattice parameters, but leads to an increased stability of metastable t-ZrO2-type products. The obtained results indicate the presence of very strong surface interactions between nickel oxide and zirconia.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

Napomena
Molecular Spectroscopy and Molecular Structure 2006 - A Collection of Papers Presented at the XXVIIIth European Congress on Molecular Spectroscopy, Istanbul, Turkey - September 3– ; 8, 2006

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