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 (Mg2+) 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.
|Titolo:||Yellow Pr-zircon pigments. The role of praseodymium and of the mineralizer|
|Parole Chiave:||Colour; Optical properties; Pigments; Sol-gel processes; X-ray methods; ZrSiO4|
|Settore Scientifico Disciplinare:||Settore CHIM/02 - Chimica Fisica|
Settore CHIM/01 - Chimica Analitica
|Data di pubblicazione:||2004|
|Digital Object Identifier (DOI):||10.1016/j.jeurceramsoc.2004.01.003|
|Appare nelle tipologie:||01 - Articolo su periodico|