Titanium and iron oxides produced by sol-gel processing of [FeCl(Ti{sub 2}(OPr{sup i}){sub 9})]: structural, spectroscopic and morphological features

Journal Article · Wed Dec 10 00:00:00 EST 2003 · Materials Research Bulletin

DOI:https://doi.org/10.1016/j.materresbull.2003.09.003· OSTI ID:20887952

Camargo, Pedro H.C.; Nunes, Giovana G; Friedermann, Geraldo R; Evans, David J; Leigh, G Jeffery; Tremiliosi-Filho, Germano; Sa, Eduardo L. de; Zarbin, Aldo J.G.; Soares, Jaisa F

The first structurally characterised titanium and iron isopropoxide, [FeCl(Ti{sub 2}(OPr{sup i}){sub 9})] (1), has been used as a single-source precursor for TiO{sub 2}/Fe{sub 2}TiO{sub 5} composites prepared by the sol-gel route. Two distinct hydrolysis and condensation conditions were employed, followed by drying and thermal treatment up to 1000 deg. C. Product composition and oxide phase transitions were characterised by powder X-ray diffractometry and Raman, electron paramagnetic resonance, Moessbauer and Fourier-transformed infrared spectroscopies. A mixture of nanometric-size TiO{sub 2} (anatase, 3.6-5.8 nm) and amorphous iron(III) oxide was obtained up to 500 deg. C, while TiO{sub 2} (rutile), {alpha}-Fe{sub 2}O{sub 3} (hematite) and Fe{sub 2}TiO{sub 5} (pseudobrookite) were found at 700 deg. C. At 1000 deg. C, only rutile and pseudobrookite were observed. These results suggest that 1 behaves as a type III single-source precursor. Powders calcined at 1000 deg. C were analysed for surface morphology, microstructure and elemental composition by scanning electron microscopy/energy dispersive X-ray spectroscopy. Results suggest no phase segregation on a sub-micrometer level. Different morphologies were observed for the materials produced by the N{sub 2} route, and this could relate to early crystal growth in an oxygen-deficient environment.

• OSTI ID: 20887952
• Journal Information: Materials Research Bulletin, Vol. 38, Issue 15; Other Information: DOI: 10.1016/j.materresbull.2003.09.003; PII: S0025540803002460; Copyright (c) 2003 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
CRYSTAL GROWTH
ELECTRON SPIN RESONANCE
FERRITES
HEAT TREATMENTS
HEMATITE
HYDROLYSIS
INFRARED SPECTRA
IRON
IRON CHLORIDES
IRON OXIDES
MICROSTRUCTURE
MORPHOLOGY
PHASE TRANSFORMATIONS
RAMAN SPECTROSCOPY
RUTILE
SCANNING ELECTRON MICROSCOPY
SOL-GEL PROCESS
TITANIUM OXIDES
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY