The dielectric and piezoelectric properties of the new perovskite solid solution system (1-x)BiScO3–xPbTiO3 were investigated. This system is representative of a new group of high temperature piezoelectrics that includes Bi(Me)O3–PbTiO3, where Me+3 is a relatively large cation, Sc, Y, Yb, In, etc., and combinations thereof. In the (1-x)BiScO3–xPbTiO3 series, perovskite stability was achieved for x>50 mol% PbTiO3 being ferroelectric rhombohedral and transforming to ferroelectric tetragonal in the region x=64 mol% PbTiO3, designated as the morphotropic phase boundary (MPB). Analogous to (1-x)PbZrO3–xPbTiO3 (PZT), the dielectric and piezoelectric properties were enhanced for compositions near the MPB. Piezoelectric coefficient d33 values reached 450 pC/N, comparable to soft PZT's with a transition temperature of 450°C, more than 100°C higher than commercial PZT. The combination of high TC and excellent piezoelectric activity make (1-x)BiScO3–xPbTiO3 materials candidates for high temperature, and temperature stable actuators and transducers.

Preparation and Characterization of High Temperature Perovskite Ferroelectrics in the Solid-Solution (1-x)BiScO3–xPbTiO3

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

Perovskite solid solution ceramics of (1 − x)BaTiO3–xBi(Mg2/3Nb1/3)O3 (BT–BMN) (x = 0.05–0.2) were synthesized by solid-state reaction technique. The results show that the BMN addition could lower the sintering temperature of BT-based ceramics. X-ray diffraction results reveal a pure perovskite structure for all studied samples. Dielectric measurements exhibit a relaxor-like characteristic for the BT–BMN ceramics, where broadened phase transition peaks change to a temperature-stable permittivity plateau (from −50°C to 300°C) with increasing the BMN content (x = 0.2), and slim polarization–electric field hysteresis loops were observed in samples with x ≥ 0.1. The dielectric breakdown strength and electrical resistivity of BT–BMN ceramics show their maxima of 287.7 kV/cm and 1.53 × 1013 Ω cm at x = 0.15, and an energy density of about 1.13 J/cm3 is achieved in the sample of x = 0.1.

Relaxor Ferroelectric BaTiO3–Bi(Mg2/3Nb1/3)O3 Ceramics for Energy Storage Application

The low-field electrical behavior of relaxor ferroelectric ceramics has been qualitatively described by many parameters, including diffuseness (δ), which characterizes the breadth of the transition peak and is roughly related to the standard deviation of the peak. Three major types of equations have been used to calculate δ: Gaussian distribution (originated by Smolenskii and Rolov et al.), power law (used by many authors), and variable power law (Uchino et al). In this work, the three calculational techniques are compared analytically and illustrated using dielectric data from ceramic 0.88Pb(Mg1/3Nb2/3)O3. 0.12PbTiO3. All three methods of analysis result in very linear plots; however, the calculated values of δ are significantly different. A method of limiting the temperature range to that corresponding to 2/3 of the maximum relative dielectric constant is suggested in order to decrease the deviations. This limitation is shown to give consistent reproducible diffuseness values without extraneous contributions arising from the relaxor nature of the material or from differing temperature ranges of measurement, thus allowing δ to be used as an effective comparative parameter for relaxor ceramics.

Diffuseness as a Useful Parameter for Relaxor Ceramics

https://dr.ntu.edu.sg/bitstream/10356/93903/2/125.%20Progress%20in%20Synthesis%20of%20Ferroelectric%20Ceramic%20Materials%20via%20High-Energy%20Mechanochemical%20Technique.pdf

Progress in synthesis of ferroelectric ceramic materials via high-energy mechanochemical technique

L'addition de BaTiO 3 permet d'eviter la formation de phase pyrochlore dans les ceramiques de PZN. On etudie la preparation, les relations de phases et les proprietes dielectriques de plusieurs compositions du systeme binaire PZN-BT

Stabilization of the perovskite phase and dielectric properties of ceramics in the Pb(Zn1/3Nb2/3)O3-BaTiO3 system

The use of Pb(Zn1/3Nb2/3)O3 ceramics is restricted by the formation of a pyrochlore phase detrimental to both dielectric and piezoelectric properties. Recently it has been shown that a 6 mol% addition of BaTiO3 to PZN suppresses the formation of pyrochlore phase. Phase relations and dielectric properties of ceramics in the PZN-BT-PT system are reported here. Compositions with the perovskite structure, having high dielectric constant and low temperature coefficient of capacitance, have been identified.

Dielectric and Ferroelectric Properties of Ceramics in the Pb(Zn 1/3Nb2/3)O3‐BaTiO3‐PbTiO3 System

Etude des effets de la temperature et de la duree de calcination sur la stabilite de la structure perovskite dans le systeme PZN-ST-PT. Preparation de ceramiques exemptes de pyrochlore a constantes dielectriques elevees par optimisation des conditions de calcination et de frittage

Phase relations and dielectric properties of ceramics in the system Pb(Zn1/3Nb2/3)O3-SrTiO3-PbTiO3

The dielectric and electrostrictive properties of relaxor ferroelectric Pb (Mg1/3Wb2/3)O3-based ceramics are strongly affected by the microstructure with emphasis on the grain size. Both the dielectric constant K and electrostrictive field coefficient (M) were found to increase with increasing grain size whereas the electrostrictive polarization coefficient Q was essentially independent of preparation. It was observed, however, that factors other than grain size, such as diffuseness of the phase transition, must also be taken into account to explain microstructural effects on various properties of relaxor dielectrics.

Grain size dependence of dielectric and electrostriction of Pb(Mg1/3Nb2/3)O3-based ceramics

Electric polarizations and elastic strain were measured simultaneously for several lead lanthanum zirconate-titanate (PLZT) compositions cycled around their high-field electric hysteresis loops. Using the accepted symbolism for compositions, where the first number gives the mole percent of La2O3 and the second two numbers give the ratio of PbZrO3 to PbTiO3 in the composition, data were taken for (7,7.5,8,8.8,9.5)/65/35 and 8/70/30 compositions. The results show that for all compositions in which the base state is macroscopically nonpolar, the strains are dominantly electro-strictive in nature. Both of the polarization-related constants, Q11 and Q12, are almost independent of temperature and of the same order as in other perovskites but decrease slightly in magnitude with increasing La2O3 content.

Umesh Kumar

Papers

Stabilization of the perovskite phase and dielectric properties of ceramics in the Pb(Zn1/3Nb2/3)O3-BaTiO3 system

Dielectric and Ferroelectric Properties of Ceramics in the Pb(Zn 1/3Nb2/3)O3‐BaTiO3‐PbTiO3 System

Phase relations and dielectric properties of ceramics in the system Pb(Zn1/3Nb2/3)O3-SrTiO3-PbTiO3

Grain size dependence of dielectric and electrostriction of Pb(Mg1/3Nb2/3)O3-based ceramics

Electrostriction in Lead Lanthanum Zirconate-Titanate Ceramics