Naslov
X-ray powder diffraction investigation of Fe-doped TiO2 samples synthesized by the sol-gel method under alkaline conditions

Autori
Gržeta, B. ; Gotić, M. ; Musić, S. ; Ivanda, M.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of abstarcts of the tenth Croatian-Slovenian Crystallographic Meeting / Danilovski, A.; Kajfež, T.; Popović, S. - Zagreb : Pliva, 2001, 25-25

Skup
Tenth Croatian-Slovenian Crystallographic Meeting

Mjesto i datum
Lovran, Hrvatska, 21.06.2001. - 24.06.2001

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
TiO2; XRD; Rietveld method

Sažetak
Titania, TiO2, is a technologically interesting material because of its catalytic and electronic properties. Its properties, however, change when it is doped with metal atoms or when prepared to have a very small crystallite size [R. J. H. Clarc, The Chemistry of Titanium and Vanadium, Elsevier Publ. Co., New York, 1968]. In this work we examined the influence of iron doping on structural properties of titania. Polycrystalline titania and Fe-doped titania samples containing 0.5, 1.1, 2.6, 8.1 and 18 at% Fe were prepared by a sol-gel technique. Ti(IV)-isopropoxide and Fe(III)-nitrate were used as precursors of titanium and iron. Synthesis was performed in a nitrogen inert atmosphere under alkaline conditions, which was accomplished by addition of NH3. As-synthesized samples were annealed at 500 °C for 2 hours. The samples were examined by X-ray powder diffraction at room temperature. Sample of pure titania was anatase (tetragonal, S. G. I41/amd). Sample with 0.5 at% Fe was an anatase-type solid solution. For Fe doping level higher than 0.5 at% Fe the samples contained two phases, that of anatase-type and of rutile-type (tetragonal, S. G. P42/mnm), respectively. Anatase phase was dominant for all the doped samples. The sample with 18 at% Fe contained impurity, namely ~5% Fe2TiO5. All the samples were nanocrystalline, with crystallite sizes in the range 10-20 nm. Diffraction line broadening increased with Fe doping level. Unit-cell parameters were determined using Si as an internal standard, and refined by the whole powder pattern fitting [WPPF program, H. Toraya, J. Appl. Cryst. 19 (1986) 440]. Iron doping increased slightly unit-cell parameters of both anatase- and rutile-type phases. The Rietveld method [H. M. Rietveld, J. Appl. Cryst. 2 (1969) 65] was performed to refine the crystal structure of obtained phases, and the real incorporation level of Fe into the anatase and rutile lattices was determined.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

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