Dielectric response of antiferroelectric PLZT 2/95/5 ceramics in the rangeof 10-10(14) Hz and 10-530K

Dielectric response of PLZT 2/95/5 ceramics was studied by classical bridge method, coaxial radio-frequency and waveguide microwave techniques, submil limetre transmission and infrared reflection spectroscopy in the temperatur e region 10-550 K. Large dielectric anomaly appears near the phase transiti on from paraelectric to incommensurate phase (T-i=470 K) due to a critical relaxation in the GHz region whose frequency softens on cooling in the para electric phase and disappears in the antiferroelectric phase below 380 K. M any new phonon modes were resolved in the infrared reflectivity spectra at 10 K due to the Brillouin zone folding in the antiferroelectric phase and d ue to the low phonon damping. Both these facts show that the antiferroelect ric phase is fully ordered.