In-situ observation on domain switching of PLZT via Raman spectroscopy

An in-situ and nondestructive technique was proposed and established for the study of domain switching in PLZT ceramics via observation of Raman spectrum changes based on the Raman light scattering principle and the soft mode theory. A Vickers indent was introduced into the polarized PLZT specimen so that the Raman spectrum change associated with the domain switching as induced either by an applied electric field or by a stress field surrounding the tip of the Vickers indent crack was in-situ measured and studied using this established technique. The relation between the domain switching and the measured Raman spectrum was discussed. It is well demonstrated that this technique can sensitively detect and measure the domain switching via the observation of Raman spectrum changes. The results confirm that Raman spectrum intensity is directly attributed to the change of the polarization direction of the incidence and scattered lights with respect to the direction of the average polarization direction of the domain in the polarized specimen. When the two directions are parallel, the induced polarizability tensor of the specimen would be enhanced and give rise to a higher intensity for Raman scattering light.