Deposition and characterization of nanoc

Solid State Ionics 138 (2001) 191–197

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Deposition and characterization of nanocrystalline tetragonal

zirconia films using electrostatic spray deposition

T. Nguyen, E. Djurado*

Laboratoire d’Electrochimie et de Physico-chimie des Materiaux et des Interfaces ´ , ENSEEG-INP Grenoble, BP 75,

1130 Rue de la piscine, Domaine Universitaire, 38402 St Martin d’Heres Cedex ` , France

Received 18 July 2000; received in revised form 18 September 2000; accepted 9 October 2000

Abstract

Pure tetragonal and nanocrystalline 2 mol.% Y O -doped ZrO thin films are deposited on stainless steel substrates by 23 2

electrostatic spray deposition (ESD) technique. Tetragonal phase is evidenced by Raman spectrometry and X-ray diffraction

in an as-deposited film at 4008C. Good homogeneity in composition is confirmed using wavelength dispersion scanning. The

surface microstructure of dense to porous thin films is investigated varying both deposition parameters: substrate temperature

and deposition time.  2001 Elsevier Science B.V. All rights reserved.

Keywords: Nanocrystalline tetragonal yttria doped zirconia; Electrostatic spray deposition; IT-SOFC

1. Introduction Moreover, it is expected that nanometric crystallite

size may show enhanced ionic conduction along the

At present, efforts are focused on lowering the grain boundaries as it was previously shown by

operating temperature of solid oxide fuel cells from Mondal et al. in tetragonal zirconia ceramics [3].

| 10008C to | 7508C (IT-SOFC). Moderate oper- Electrostatic atomization of liquids has been large￾ating temperatures, however, require noticeable de- ly used in the painting industry for many years.

crease of electrolyte resistance. In this context, thin Recently, this technique has been applied mainly for

films of nanocrystalline tetragonal yttria doped zir- a variety of functional metal oxides in SOFCs such

conia have been prepared by electrostatic spray as cubic Y O stabilized ZrO , LaCoO , BaCeO 23 2 3 3

deposition (ESD). In this study, tetragonal zirconia and in solid-state rechargeable lithium-ion batteries

has been preferred for two reasons: (i) the excellent such as LiCoO , LiMn O , Li PO , TiO , MnO 2 2 4 3 42 2

ionic conductivity in the low temperature domain up and SnO for example [4–10]. The advantages of 2

to 7508C compared to cubic zirconia [1,2], (ii) the this technique are a simple set-up, a wide choice of

better mechanical properties (high strength, high precursors, relatively large film growth rate, ambient

toughness and wear resistance) than the cubic form. atmosphere operation, a good control of the mor￾phology of the deposited layers and an excellent

control of stoichiometry [8] compared to other *Corresponding author. Tel.: 133-4-7682-6684; fax: 133-4-

7682-6670. deposition techniques such as RF sputtering, sol–gel,

E-mail address: [email protected] (E. Djurado). CVD or MOCVD and injection-LPCVD.

0167-2738/01/$ – see front matter  2001 Elsevier Science B.V. All rights reserved.

PII: S0167-2738(00)00795-5