Title

Mechanical Behavior And Electrical Conductivity Of La1-XCaXCoo3 (X = 0, 0.2, 0.4, 0.55) Perovskites

Keywords

Bending strength; Conductivity; Ferroelasticity; Fracture toughness; Modulus; Perovskite

Abstract

This paper compares the important mechanical properties and the electrical conductivities from room temperature to 800 °C of four LaCoO3 based cobaltite compositions with 0, 20, 40 and 55% Ca2+ ions substituted on the A site of the perovskite structure respectively. Ca2+ doped lanthanum cobaltite materials are strong candidates for use as cathodes in lower temperature solid oxide fuel cells operating at or below 800 °C. Among these four cobaltite compositions, two (LaCoO3 and La0.8Ca0.2CoO3) were found to be phase pure materials, whereas the remaining two compositions (La0.6Ca0.4CoO3 and La0.45Ca0.55CoO3) contained precipitation of secondary phases such as CaO and Co3O4. The mechanical properties of the four compositions, in terms of Young's modulus, four-point bending strength and fracture toughness measurements, were measured at both room temperature and 800 °C. At room temperature, doping with Ca2+ was found to substantially increase the mechanical properties of the cobaltites, whereas at 800 °C the pure LaCoO3 composition exhibited higher modulus and strength values than La0.8Ca0.2CoO3. All of the four compositions exhibited ferroelastic behavior, as shown by the hysteresis loops generated during uniaxial load-unload compression tests. Electrical conductivity measurements showed the La0.8Ca0.2CoO3 composition to have the highest conductivity among the four compositions. © 2009 Elsevier B.V. All rights reserved.

Publication Date

6-1-2010

Publication Title

Journal of Power Sources

Volume

195

Issue

11

Number of Pages

3612-3620

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1016/j.jpowsour.2009.11.134

Socpus ID

75749115468 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/75749115468

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