Stabilization of tetragonal zirconia nanocrystallites using an original supercritical-based synthesis route
Langue
en
Article de revue
Ce document a été publié dans
Chemistry of Materials. 2020, vol. 32, n° 19, p. 8169-8181
American Chemical Society
Résumé en anglais
To understand the importance of the particle size on the stabilization of metastable tetragonal ZrO2, ultrafine ZrO2 nanocrystals were synthesized via (i) the precipitation method in supercritical water using nitrate ...Lire la suite >
To understand the importance of the particle size on the stabilization of metastable tetragonal ZrO2, ultrafine ZrO2 nanocrystals were synthesized via (i) the precipitation method in supercritical water using nitrate precursors, (ii) the sol–gel method in a supercritical ethanol–water mixture, and (iii) the borderline nonhydrolytic sol–gel route in supercritical ethanol using propoxide precursors. The obtained nanocrystals displayed a variation of the monoclinic versus tetragonal molar fractions from 100 wt % down to ≈10 wt % of monoclinic phase. This variation was concomitant with an overall size decrease of the nanocrystals, ranging from 7 to 2 nm depending on the synthesis procedures. Phase contents were quantified by refinement analysis of X-ray scattering data sets and crosschecked with Raman spectroscopy. Our results suggest that an upper limit of ≈90 wt % of the tetragonal ZrO2 phase is possible, even for ultrafine nanoparticles (2 nm). These findings thus question the existence of any critical size limit below which stabilization of pure t-ZrO2 is attainable at low temperatures.< Réduire
Mots clés en anglais
Granular materials
Precursors
Nanoparticles
Ethanol
Physical and chemical processes
Origine
Importé de halUnités de recherche