In-situ Raman spectroscopic study of domain switching of PLZT ceramics

A specially designed apparatus was used to observe in-situ domain switching in lanthanum-doped lead zirconate titanate (PLZT) ceramics by Raman spectroscopy. Using the established technique, the variations in measured Raman spectrum of unpoled and appropriately poled PLZT ceramics under the application of dc voltage and during the process of electric fatigue were examined. It was confirmed that the intensity change in the soft mode of the Raman band is highly dependent on the orientation of the domain switching with respect to the polarization direction of Raman incident light. When the orientation of the specimen with respect to propagation directions (including polarization direction) of incident light and scattered light is appropriate, the Raman spectroscopy can allow a non-destructive and in-situ measurement of the domain switching in a microscopic scale. The relation between the domain switching and the measured Raman spectrum change is discussed for PLZT polycrystalline materials by developing criteria extended from a single-crystal model.