Creep of Lanthanum Gallate

Published

March 1, 2002

Author(s)

William E. Luecke, T R. Armstrong

Abstract

Strontium- and magnesium-doped lanthanum gallate (LSGM) was deliberately prepared to give A-site deficient non-stoichiometry with compositions (La_0.9Sr_0.1)z(Ga_0.8Mg_0.2)O_3-delta (z =1.0,0.98, and 0.95). Creep tests in four-point 950 C 75 Mpa in air demonstrated that all three compositions shared a common stress dependence, n = 1.49 0.10, and a common apparent activation energy, Q = 426 9 kJ/mol. Despite this agreement, the creep rates of the different compositions depended on grain size in different ways: p = 3.1 0.2 for z = 0.98, and p = 1.9 0.1 for z = 0.95. The measured apparent activation energy, Q for creep is similar, though statistically significantly smaller, than that measured in another LSGM. Both are nearly twice as large as reported activation energies for cation impurity diffusion. The absolute magnitude of the creep rates, after correction for grain size, were 30 to 100 times slower than in another LSGM of similar composition.

Citation

Journal of Materials Research

Volume

17

Issue

No. 3

Pub Type

Journals

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Keywords

magnesium-doped lanthanum gallate

Citation

Luecke, W. and Armstrong, T. (2002), Creep of Lanthanum Gallate, Journal of Materials Research, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=850516 (Accessed October 10, 2025)