THE INVESTIGATION OF LOW-FREQUENCY ACOUSTIC PROPERTIES OF FERROELECTRICS AND FERROELASTICS BY TORSION PENDULUM TECHNIQUE

The features of infrasonic frequency (10 3-10> Hz) internal friction, Q~1, and shear modulus, G, in different ferroelectric and ferroelastic crystals have been studied using the inverse torsion pendulum technique over a wide temperature range and different external fields which lead to the change of a real crystal structure. It is shown that the anomalous behavior of and G at infralow frequencies to a great extent depends on crystal lattice imperfections (dislocations, point defects, domain and interphase boundaries). Physical mechanisms responsible for this behavior are discussed. © 1990, Taylor & Francis Group, LLC. All rights reserved.