Targeted Basic Studies of Ferroelectric and Ferroelastic Materials for Piezoelectric Transducer Applications

摘要

The work reported covers the fifth and final year of the program of Targeted Basic Studies of Ferroelectric and Ferroelastic Materials for Piezoelectric Transducer Applications. Major achievements include the development of a physical approach to understanding active composites, leading to the development of several new families of PZT:polymer piezoelectric composites for hydrophone application. New advances in the phenomenology and microscopic theory of electrostriction, and the evolution of a new family of high strain ferroelectric relaxor materials for practical application. New basic understanding of the polarization mechanisms in ferroelectric relaxors has been aided by the study of order-disorder of the cation arrangement in lead scandium tantalate, and the results correlate well with studies of relaxor behavior, and of shape memory effects in PLZT ceramics. Low temperature studies on pure and doped PZTs have given the first clear indication of the intrinsic (averaged) single domain in response and correlate exceedingly well with earlier phenomenological theory. Crystal growth and ceramic processing studies have developed 'hand-in-hand' with program needs providing new forms of conventional materials, new grain oriented structures and single crystals.