Nanostructure, nanochemistry and grain boundary conductivity of yttria-doped zirconia

Alin Rizea ,  Jean-Marc Raulot ,  Claude Petot ,  Georgette Petot-Ervas ,  Gianguido Baldinozzi 

Ecole Centrale Paris, SPMS, UMR CNRS-ECP (ECP), Grande voie des vignes, Chatenay-Malabry 92295, France


This work is aimed to a comprehensive study of the role of the microstructure and of the local chemistry at the grain-boundaries on the ionic grain-boundary conductivity in yttria (9mol%)-stabilized zirconia (YSZ) and in YSZ-alumina composites. Electrical conductivity measurements show that the grain-boundary conductivity (σgb) increases with the cooling rate at the end of sintering, when the grain size and the amount of Si in the ceramic decreases. Alumina additions lead to a decrease of σgb in the samples containing 1.0 wt% SiO2, while σgb passes through a maximum for heavier silicon contents. These results, coupled to TEM X-ray microanalysis, suggest that alumina nanoparticles interact strongly with SiO2 at the grain boundaries giving rise to a competitive effect: whereas the alumina nanoparticles increase the insulating character, they also reduce the vitreous phase at the grain boundaries, increasing the conductivity. Moreover, XPS analyses show that Si and Y segregate near the interfaces, on a depth smaller than 600nm. These analyses suggest a kinetic demixing process and they allow to explain the positive effect of a faster cooling rate at the end of sintering, responsible for the smaller amount of Si rejected at the grain-boundaries.

Legal notice
  • Legal notice:

    Copyright (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: must be provided.


Related papers
  1. Characterization of radiation defects in transparent oxides
  2. Phase stability in nanocrystalline zirconia

Presentation: poster at E-MRS Fall Meeting 2004, Symposium G, by Gianguido Baldinozzi
See On-line Journal of E-MRS Fall Meeting 2004

Submitted: 2004-04-30 18:56
Revised:   2009-06-08 12:55
© 1998-2022 pielaszek research, all rights reserved Powered by the Conference Engine