This review of the PLZT materials and their applications describes the present state of the technology and emphasizes the latest developments in the field of electrooptic ceramics. Despite the reported development of new, transparent materials in other compositional systems, the PLZT's still remain the standard of the industry and continue to find an ever increasing number of applications in the areas of shutters, filters, displays, and spatial light modulators. Their fast response, high resolution and wide operating temperature range make them viable candidates for several emerging technologies including high resolution, non-impact, facsimile printing, electrophotographic copying, color reproduction and integrated optical processing. With the presently successful development of sputtered PLZT thin films, both bulk and thin film PLZT materials can now be considered for future electrooptic devices.

PLZT electrooptic materials and applications: a review

A review is given concerning up-to-date methods of the transparent ferroelectric ceramics (TFC) production (chemical coprecipitation of raw material, two-stage hot-pressing, etc.), its application in optoelectronic devices (large-aperture modulators, linear light gate arrays, segmented displays) and possible new developments (near IR modulators including). Specific features of the TFC physical properties (optical parameters, photorefraction) are analyzed, the nature of the diffused phase transition in PLZT ceramics and related studies being discussed.

Transparent ferroelectric ceramics: Properties and applications

The electrocaloric effect in rhombohedral PLZT ceramics is studied as function of applied field and temperature. The results obtained are consistent with the general idea of the existence of an intermediate state of mixed polar and nonpolar regions in the interval of the diffuse phase transition. The step-like change of the temperature at the field-induced first-order phase transition in the temperature range close to Tt corresponds to an entropy jump of 0.18 × 10-2 J/cm3 · deg.

Electrocaloric effect in PLZT ceramics

PLZT and PSN ceramics have been exposed to γ-radiation (energy ≈ 1.15 MeV, dose up to 3 · 109 rad), electron flux (≈4.5 MeV, dose up to 3.1018 electr./cm2) and fast neutrons (≥ 0.1 MeV, dose up to 1018 n/cm2). The irradiated material was used to study radiation effects on dielectric parameters (e and tgδ were measured at frequencies from 1 kHz to 5 MHz), polarization (dielectric hysteresis quasistatic loops) and non-linear optical properties (I2w). The measurements were made in the region of phase transition as well as to examine annealing of radiation-induced defects. As compared to PLZT the PSN ceramics is more resistant to radiation, the most sensitive PLZT compounds being with 7 ≤ × ≤ 9.5 at .% of La. Obtained results are explained by the change of ion charge, redistribution of vacancies in A and B sublattices of PLZT and by possible ion ordering in sublattice B of PSN with account for intrinsic fields in the relevant compounds.

Radiation-induced effects in transparent ferroelectric ceramics

EXAFS, X-ray diffraction and Raman studies of (Pb1−xLax)(Zr0.65Ti0.35)O3 (x=0.04 and 0.09) ceramics irradiated by high-current pulsed electron beam

The phase transition in PLZT X/65/35 solutions is considered as a diffuse transformation characterized by the two processes comprising it—distortion of the symmetric structure and domain formation. Transparent PSN ceramics are reported to be a promising material in matrix addressing devices due to a low operating voltage and a high P t/P t, ratio.

A. Y. Dobre

Papers

Transparent ferroelectric ceramics: Phase transitions and new materials