Yellow Pr-zircon pigments: The role of praseodymium and of the mineralizer

• Published in: Journal of the European Ceramic Society Vol. 24; no. 14; pp. 3603 - 3611
• Main Authors: Del Nero, Giulia, Cappelletti, Giuseppe, Ardizzone, Silvia, Fermo, Paola, Gilardoni, Stefania
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.11.2004; Elsevier
• Subjects: Applied sciences; Chemical industry and chemicals; Colour; Dyes, pigments; Exact sciences and technology; Industrial chemicals; Optical properties; Pigments; Sol–gel processes; X-ray methods; ZrSiO 4; Pigments; Sol–gel processes; X-ray methods; Optical properties; ZrSiO 4; Colour; Scanning electron microscopy; Inorganic pigment; Mineralizing agent; Transition element compounds; Doping; Zirconium silicate; Silicates; Experimental study; X ray diffraction; Powder; Zircon; Inorganic compound; Characterization; Additive; Praseodymium addition; Sol gel process; Chemical preparation; Growth from solution; Coloration
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2004.01.003

A sol–gel reaction starting from Si and Zr alkoxides, in water–ethanol mixtures, was employed to obtain praseodymium doped zirconium silicate powders (zircon). The reactions were performed by modulating both: (a) the amount of praseodymium salt in the starting mixture and (b) the speciation of the mineralizers; chloride and fluoride salts of monovalent (Na +, Li +) and divalent (Mg 2+) were tested. The products of the sol–gel reaction were calcined either at 1000 °C or at 1200 °C. The samples were characterised by X-ray diffraction, SEM micrographs, EDX analyses and diffuse reflectance spectroscopy; the colour of the pigments was characterized on the grounds of the Commission Internationale de l’Eclairage (CIE) standard procedure (CIE L ∗ a ∗ b ∗ measurements). Results from the structural, morphological and optical characterisations are examined and cross-compared to produce a consistent picture of the key factors leading to the formation, growth and optical properties of the reaction products.