On the mechanisms of microcracking in ferroelectric ceramics

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:395196

Jiang, Q ^[1]

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1. Univ. of Nebraska, Lincoln, NE (United States)

Ferroelectric oxide ceramics, such as barium titanate, PZT and PLZT, have recently attracted great attention because they are desirable materials for smart actuators. Experiments indicate that the cause for the most commonly encountered failure of these ceramics is microcracking. Growth of microcracks under electrical and/or mechanical loading in applications of ferroelectric actuators leads to macroscopic fracture or electric breakdown which can result in catastrophic damage to the systems with such devices. The present investigation represents an effort to understand the mechanism of formation and growth of microcracks in these ceramic materials. The analysis suggests that the sources of microcracks are the internal stresses along the 90{degree} domain walls and at the intersections of the domain walls with grain boundaries. These internal stresses arise from the incompatibility of constraints of grain boundaries with the lattice distortion associated with the formation of 90{degree} domains which occurs immediately after the paraelectric-ferroelectric phase transformation. This notion is supported by a number of experimental observations.

• OSTI ID: 395196
• Report Number(s): CONF-940691--; ISBN 1-56676-171-9
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
ACTUATORS
CRACK PROPAGATION
DOMAIN STRUCTURE
FERROELECTRIC MATERIALS
MATERIALS
PLZT
PZT