Interaction of ferroelectric twins with grain boundaries

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:175098

Jiang, Q ^[1]

---

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

Experimental investigations suggest that microcracking may be the major cause for the commonly-encountered degradation of ferroelectric actuators, namely electric fatigue. The present analysis, based upon the lattice distortions occurring during the formation of electric twins, indicates that intersections of domain walls with grain boundaries are likely to be origins of microcracks because of the concentrations of stress and electric fields arising due to the incompatibility of the lattice distortions with the grain boundary constraints. This further motivated an asymptotic analysis on the stress and electric field concentrations near intersections of domain walls with grain boundaries. This analysis is carried out within a framework of electrostatics for deformable continua. Assuming that the electromechanical state in each of the ferroelectric domains is slightly distorted from one of the natural states of the crystal, the authors developed a piecewise linearized model for which concentrations of stress and electric fields correspond to singularities of these fields. The asymptotic analysis concludes that both the stress and electric fields exhibit a power-law singularity. Several examples indicate that the order of singularity depends upon the crystal orientation and the orientations of the domain walls with respect to the grain boundary which they intersect. The work presented here is a summary of the author`s investigation on this subject in collaboration with Y. Zhang in 1994.

• OSTI ID: 175098
• Report Number(s): CONF-950686--; CNN: Grant N00014-94-1-0053; Grant MSS9308341; Grant LWT/11-154-05101
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTUATORS
CRACKS
ELECTRIC FIELDS
ELECTROSTATICS
FATIGUE
FERROELECTRIC MATERIALS
GRAIN BOUNDARIES