Time-resolved diffraction measurements of electric-field-induced strain in tetragonal lead zirconate titanate

The dynamic electric-field-induced strain in piezoelectric ceramics enables their use in a broad range of sensor, actuator, and electronic devices. In piezoelectric ceramics which are also ferroelectric, this macroscopic strain is comprised of both intrinsic (piezoelectric) and extrinsic (non-180 degrees domain switching) strain components. Extrinsic contributions are accompanied by hysteresis, nonlinearity, and fatigue. Though technologically significant, direct measurement of these mechanisms and their relative contributions to the macroscopic response has not yet been achieved at driving frequencies of interest. Here we report measurements of these mechanisms in ceramic lead zirconate titanate during application of subcoercive cyclic driving electric fields using an in-situ stroboscopic neutron diffraction technique. Calculations are made from the diffraction measurements to determine the relative contributions of these different strain mechanisms. During applied electric field square waves of +0.5E(c) unipolar and +/- 0.5E(c) bipolar, at 1 Hz, non-180 degrees domain switching is found to contribute 34% and 40% of the macroscopically measured strain, respectively. (C) 2007 American Institute of Physics.