Structural Behavior of Zirconia Thin Films with Different Level of Yttrium Content

Abstract

The preparation of dense, high conductive electrolyte layers is important for the development of intermediate temperature solid oxide fuel cells and other devices based on oxygen-ion conductivity. Thus a number of techniques have been used to produce these structures. This study makes use of one of these methods to produce dense nanocrystalline 0.1 to 1 micron layers of zirconia. Polymeric precursors were used to prepare zirconia films with different level of yttrium substitution. the films were annealed at a series of temperatures in the range of 400 to 1000°C and were characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that initially (after 400°C annealing) the films had cubic structure and grain size of ∼5 nm regardless of Y content. the situation changed when the annealing temperature was increased. Y (16mol %) stabilized zirconia (YSZ) did remain cubic over the entire temperature region investigated (up to 1000°C), but for compositions with lower Y content changes in crystal structure occurred. the samples with 4 and 8mol% Y transformed to the tetragonal phase at about 700°C, and undoped zirconia became monoclinic at the same temperature. the results were compared with sintered zirconia and it was shown that the behavior of thin films is quite similar to that of the sintered material, if the annealing temperature was high enough (< 700°C). the main differences between polymeric prepared films and sintered material are the existence of the cubic structure at low temperatures (< 600°C) and lower transition temperatures to the high temperature phase, which can be explained by small initial grain size in polymer-derived zirconia.

Department(s)

Materials Science and Engineering

Second Department

Chemistry

International Standard Serial Number (ISSN)

0272-9172

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 Materials Research Proceeding, All rights reserved.

Publication Date

01 Jan 2003

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