Effect of Two-Dimensional Mechanical Stress on the Dielectric Properties of Poled Ceramic Barium Titanate and Lead Zirconate Titanate

Studies have been made of the dielectric behavior of several ferroelectric ceramic materials when a two-dimensional stress was applied normal to the axis of polarization. It has been shown that the dielectric constant decreases and the dielectric loss increases with increasing stress, part of the change being irreversible and part reversible. Upon application of stress to a sample, the dielectric constant did not change instantaneously but appeared to decrease linearly with the logarithm of time. Mechanisms are suggested for the observed effects.