Zirconium titanate-stannate doped with V with co-dopants Al, In, or Y was synthesized by solid state reaction and its structural (XRD, SEM), optical (DRS) and technol. properties were detd. to assess its potential use as ceramic pigment. These compds. have a srilankite-type, disordered orthorhombic structure, implying a random distribution of Zr, Ti, Sn, and dopants in a single, strongly distorted octahedral site. Doping caused an increase of unit-cell dimensions, metal-oxygen distances and octahedron distortion. Optical spectra show crystal field electronic transitions of V4+ as well as intense bands in the blue-UV range due to V4+-V5+ intervalence charge transfer and/or to V-O charge transfer. The formation of oxygen vacancies is supposed to compensate the occurrence of V4+ ensuring the lattice charge neutrality. These srilankite-type oxides develop a deep and brilliant yellow shade with colorimetric parameters close to those of industrial ceramic pigments. Technol. tests in several ceramic applications proved that zirconium titanate-stannate is very stable at high temp., exhibiting an excellent performance in the 1200-1250 range, even better than praseodymium-doped zircon.
High-performance yellow ceramic pigments Zr(Ti1-x-ySnx-yVyMy)O-4 (M = Al, In, Y): Crystal structure, colouring mechanism and technological properties
CRUCIANI, Giuseppe
2007
Abstract
Zirconium titanate-stannate doped with V with co-dopants Al, In, or Y was synthesized by solid state reaction and its structural (XRD, SEM), optical (DRS) and technol. properties were detd. to assess its potential use as ceramic pigment. These compds. have a srilankite-type, disordered orthorhombic structure, implying a random distribution of Zr, Ti, Sn, and dopants in a single, strongly distorted octahedral site. Doping caused an increase of unit-cell dimensions, metal-oxygen distances and octahedron distortion. Optical spectra show crystal field electronic transitions of V4+ as well as intense bands in the blue-UV range due to V4+-V5+ intervalence charge transfer and/or to V-O charge transfer. The formation of oxygen vacancies is supposed to compensate the occurrence of V4+ ensuring the lattice charge neutrality. These srilankite-type oxides develop a deep and brilliant yellow shade with colorimetric parameters close to those of industrial ceramic pigments. Technol. tests in several ceramic applications proved that zirconium titanate-stannate is very stable at high temp., exhibiting an excellent performance in the 1200-1250 range, even better than praseodymium-doped zircon.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.