An analysis of domain reorientation in PLZT ceramics by in situ Raman spectroscopy

An in situ Raman spectroscopy in a parallel y(z,z)y configuration was employed to investigate the domain reorientation of unpoled lanthanum-doped lead zirconate titanate (PLZT) ceramics under the dc electric field of 2000 V/mm. It was found that the relative intensity ratio I_E(2TO)/I_{E(3TO+2LO)+B1} of Raman optical modes varied periodically by 180° with the polarized direction of the laser beam. The maximum change in the intensity ratio may be correlated with the extent of the polarization within the PLZT ceramics. Upon taking the effects of the long-range electric fields associated with the polar vibrations into consideration, a formula is developed to describe the variations in the intensity ratio I_E(2TO)/I_{E(3TO+2LO)+B1}, and the average orientation within the examined grain during the application of electric field is further evaluated to be ∼33.8°.