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RESEARCH PRODUCT

Microstructure of Fe–ZrSiO4 solid solutions prepared from gels

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Abstract Microstructural changes associated with chemical and structural evolution from gels to Fe x –ZrSiO 4 solid solutions are reported. Mineralizer-free Fe x –ZrSiO 4 gels in the compositional range 0 ≤  x  ≤ 0.15 were prepared by sol–gel liquid-phase route from mixtures of alkoxides of silicon and zirconium, and iron (III) acetylacetonate, and annealed at different temperatures and/or times. The first step on the whole process to the final Fe x –ZrSiO 4 solid solutions was the formation of aggregated of tetragonal Fe-doped ZrO 2 nanocrystals with diameters smaller than 50 nm. At this stage the tetragonal Fe–ZrO 2 were embedded in amorphous silica resulting nanocomposite materials. The formation of the final Fe x –ZrSiO 4 solid solution nanocrystals at around 1100 °C occurred almost simultaneously to the Fe–ZrO 2 solid solution phase transformation from the tetragonal to the monoclinic form. The microstructural examination of specimens after annealing at 1200 °C revealed the development of Fe-doped zircon nanoparticles smaller than 100 nm.