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Accession Number:
ADA279567
Title:
Domain Processes in Ferroelectric Ceramics
Descriptive Note:
Final rept. 30 Sep 1991-31 Dec 1993
Corporate Author:
PENNSYLVANIA STATE UNIV UNIVERSITY PARK
Report Date:
1994-04-14
Pagination or Media Count:
77.0
Abstract:
This report outlines the progress achieved during a two year effort sponsored by the AFOSR on the theoretical study of domain and domain wall formation in ferroelectrics. Understanding on domain formation and domain dynamics in ferroelectrics are crucial for developing better functional ceramic materials for transducers and actuators. A continuum model has been developed to describe the polarization profile in ferroelectrics, which takes into account both nonlinear and nonlocal nature of the ferroelectric system. The theory can give rise to twin and twin band solutions under proper boundary conditions. A theoretical model is also developed for the morphotropic phase boundary in PZT system, which provides a new interpretation on the phase coexistence in a complete solid solution system. According to the new definition, the width of the coexistence region is inversely proportional to the volume of the coherent region, such as the particle size for a fine grain system. Theoretical interpretation is provided to the electron interference pattern across a ferroelectric domain wall in holographic electron microscopy, a newly developed technique with much higher magnification than the conventional TEM. The relationship between microscopic lattice dynamics and the continuum theory is also established.
Distribution Statement:
APPROVED FOR PUBLIC RELEASE
