Chromium and yttrium-doped magnesium aluminum oxides prepared from layered double hydroxides

• Published in: Solid state sciences 2007-12, Vol.9 (12), p.1115-1125
• Main Authors: García-García, J.M., Pérez-Bernal, M.E., Ruano-Casero, R.J., Rives, V.
• Format: Article
• Language: English
• Subjects: Ceramic pigments; Chromatic coordinates; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Hydrotalcite; Layered double hydroxides; Materials science; Materials synthesis; materials processing; Physics
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/j.solidstatesciences.2007.07.029

Layered double hydroxides with the hydrotalcite-like structures, containing Mg 2+ and Al 3+, doped with Cr 3+ and Y 3+, have been prepared by precipitation at constant pH. The weight percentages of Cr 3+ and Y 3+ were 1, 2, or 3%, and 0.5 or 1%, respectively. Single phases were obtained in all cases, whose crystallinity decreased as the content in Cr and Y was increased. The solids have been characterised by element chemical analysis, powder X-ray diffraction, thermal analyses (differential, thermogravimetric and programmed reduction), FT-IR and UV–vis spectroscopies; the specific surface areas have been determined from nitrogen adsorption isotherms at −196 °C. Upon calcination at 1200 °C for 5 h in air all solids display a mixed structure (spinel and rock salt for MgO); these solids have also been characterised by these techniques and their chromatic coordinates (CIE – L ∗ a ∗ b ∗) have been determined. Their pink colour makes these solids suitable for being used as ceramic pigments. [Display omitted]