Ferroelastic Behavior of LaCoO3-Based Ceramics

LaCoO3 and La0.8Ca0.2CoO3 ceramics show a nonelastic stress–strain behavior during four‐point bending experiments where hysteresis loops are observed during loading–unloading cycles. Permanent strain is stored in the material after unloading, and a mechanism related to ferroelastic domain switching...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the American Ceramic Society 2001-09, Vol.84 (9), p.2029-2033
Main Authors: Kleveland, Kjersti, Orlovskaya, Nina, Grande, Tor, Moe, Anne Marie Mardal, Einarsrud, Mari-Ann, Breder, Kristin, Gogotsi, George
Format: Article
Language:English
Subjects:
Applied sciences
Building materials. Ceramics. Glasses
Ceramic industries
Chemical industry and chemicals
cobalt/cobalt compounds
Exact sciences and technology
ferroelastic materials
Miscellaneous
strain
stress
Technical ceramics
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:LaCoO3 and La0.8Ca0.2CoO3 ceramics show a nonelastic stress–strain behavior during four‐point bending experiments where hysteresis loops are observed during loading–unloading cycles. Permanent strain is stored in the material after unloading, and a mechanism related to ferroelastic domain switching in the rhombohedral perovskite is proposed. Domain switching in the materials has been confirmed using X‐ray diffractometry. Fracture toughnesses of La0.8Ca0.2CoO3 measured using single‐edge notched beam and single‐edge V‐notched beam methods coincide and are equal to 2.2 MPa·m1/2 at room temperature and decrease to ∼1 MPa·m1/2 at temperatures >300°C. A decrease in fracture toughness is consistent with ferroelastic behavior, because the rhombohedral distortion decreases with increasing temperature.
ISSN:0002-7820
1551-2916
DOI:10.1111/j.1151-2916.2001.tb00953.x