A research program to enhance the scientific knowledge and control of acoustic wave propagation in periodically poled ferroelectric domains is proposed. These authors speculated that the acoustic memory effect might be tied to the pinning and relaxation of ferroelectric domain walls within the crystal. The physical model is definitely very speculative at this point and requires experimental verification. The objective of this proposed research is to verify the pinning and relaxation of domain walls as a source of acoustic memory observed in LiNbO3. Another objective is to develop a basic understanding of the role of domain walls on acoustic wave propagation, reflection and nonlinear effects. Also, acoustic wave detection may provide a sensitive nondestructive method for imaging of ferroelectric domains.
The application of ferroelectric crystals like LiNbO3 and LiTaO3 with periodic domain structures gives the possibility of realizing a new class of acoustoelectronic devices such as SAW transducers, filters, delay lines, frequency standards and analog signal processing. Because of the large optic nonlinearities, the crystals can be used in devices such as electro-optic modulators, parametric oscillators, and harmonic generators. Also, the piezoelectric properties allow application in the accelerometers, x-y positioners, ultrasonic cleaners, gas sensors, and ultrasonic wire bonders.
In addition to advancing the development of the science, engineering, and manufacturing technology in ferroelectric materials, the proposed research will find applications in educational activity such as in the development of a course on optoelectronic materials, devices and applications as well as practical applications.
