Transformation of yttrium-doped hydrated zirconium into tetragonal and cubic nanocrystalline zirconia

Citation
X. Bokhimi et al., Transformation of yttrium-doped hydrated zirconium into tetragonal and cubic nanocrystalline zirconia, J SOL ST CH, 142(2), 1999, pp. 409-418
Citations number
41
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Inorganic & Nuclear Chemistry
Journal title
JOURNAL OF SOLID STATE CHEMISTRY
ISSN journal
0022-4596 → ACNP
Volume
142
Issue
2
Year of publication
1999
Pages
409 - 418
Database
ISI
SICI code
0022-4596(19990201)142:2<409:TOYHZI>2.0.ZU;2-R
Abstract
Nanostructured yttrium-stabilized zirconia powders, with yttria concentrati ons between 0.0 and 10.0 mol%, were prepared via the hydrolysis of an aqueo us solution of zirconyl and yttrium chloride, and ammonium hydroxide. Powde r phases were characterized by using X-ray powder diffraction; their crysta lline structures were refined with the Rietveld technique. When samples wer e annealed below 200 degrees C, their diffraction patterns corresponded to an amorphous atom distribution and were independent of yttria concentration . The doped amorphous phases crystallized, at 400 degrees C, into tetragona l or cubic nanocrystalline zirconia, which were stabilized by yttrium, Thes e results suggest that yttrium atoms served as a substitute for zirconium a toms not only in the crystalline phases but also in the amorphous phases, w hich are determined by the fast condensation of zirconyl clusters, Non-dope d samples contained a mixture of monoclinic and tetragonal nanocrystalline zirconia; those with 2.5 to 5.0 mol% yttria contained only the tetragonal z irconia nanophase, and those with 7.5 to 10.0 mol% had only the nanocrystal line cubic phase. The average crystallite size of the nanophases diminished when Y2O3 concentration was increased. (C) 1999 Academic Press.