Influence of precursors on formation of TiO2–CrTaO4 rutile solid solutions
Authors: Tena, M.A.; Llusar, M.; Badenes, J.A.; Vicente, M.; Monrós, G.
Source: British Ceramic Transactions, Volume 99, Number 5, May 2000 , pp. 219-224(6)
Publisher: Maney Publishing
Abstract:Rutile solid solutions Crx Ti1-2xTaxO2 (0 < x < 0·5) have been synthesised by: firing mixtures of Cr2O3 , Ta2O5 , and TiO2 (anatase); firing colloidal gels obtained from TiCl4 , TaCl5 , and CrCl3 . 6H2O; and firing polymeric gels prepared from Ti4+ isopropoxide, Ta5+ethoxide, and Cr3+ acetylacetonate at 300–1300°C. Samples were characterised by XRD, differential thermal and thermogravimetric analysis, UV visible spectroscopy, Cielab colour parameter measurements, and electron microscopy. In samples synthesised from oxide mixtures, CrTaO4 (rutile structure) appeared as an intermediate phase in the formation of the solid solutions and a positive departure from Vegard's law was observed. Ta2O5 segregation in gel samples seems to prevent the formation of material consisting only of rutile. The distortion of MO6 octahedra varies as x increases. The chemical, structural, and thermal stability, and the colouration obtained on glazes containing 3 wt-%samples, indicate their potential for use as ceramic pigments. Under the experimental conditions used, the materials prepared by sol–gel synthesis were not found to be better than those prepared from oxide mixtures.
Document Type: Regular Paper
Affiliations: Inorganic and Organic Chemistry Department, Jaume I University, Castellón, Spain
Publication date: 2000-05-01