Anomolus Shrinkage of Lanthanum Strontium Manganite

Abstract

Anomalous shrinkage behavior of porous Sr-doped lanthanum manganite (La 1-xSr x) 1-y MnO 3+δ, or LSM, where x = 0.0 to 0.4) has been studied as a function of thermal cycling, oxygen partial pressure, and Sr dopant concentration. an anomalous shrinkage due to thermal cycling in doped lanthanum manganite perovskite has previously been reported in the temperature range of 600°C to 1000°C. 1,2 However, the shrinkage reported here was in a 150°C range. Shrinkage of LSM during PO 2 cycling between air (2x10 5ppm O 2) and N 2 (10ppm), was much less pronounced than that of thermal cycling in the same temperature range. the two cannot be directly compared due to the difference in cycling time. the effect of Sr dopant concentration on the shrinkage due to thermal cycling reached a maximum at a dopant level of 0.1. the postulated mechanism responsible for anomalous shrinkage is the metal ion vacancy gradient produced by the oxygen nonstoichiometry of LSM. Along with this gradient or driving force for metal ion vacancy diffusion; shrinkage also requires vacancy mobility or thermal excitation to advance the anomalous shrinkage.

Department(s)

Materials Science and Engineering

International Standard Serial Number (ISSN)

0196-6219

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 The American Ceramic Society, All rights reserved.

Publication Date

01 Dec 2005

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