Crystallographic texturing of polycrystalline ferroelectric ceramics offers a means of achieving significant enhancements in the piezoelectric response. Templated grain growth (TGG) enables the fabrication of textured ceramics with single crystal-like properties, as well as single crystals. In TGG, nucleation and growth of the desired crystal on aligned single crystal template particles results in an increased fraction of oriented material with heating. To facilitate alignment during forming, template particles must be anisometric in shape. To serve as the preferred sites for epitaxy and subsequent oriented growth of the matrix, the template particles need to be single crystal and chemically stable up to the growth temperature. Besides templating the growth process, the template particles may also serve as seed sites for phase formation of a reactive matrix. This process, referred to as Reactive TGG (RTGG), has been used to obtain highly oriented Pb(Mg1/3Nb2/3)O3-PbTiO3, Sr0.53Ba0.47Nb2O6, and (N...

Templated Grain Growth of Textured Piezoelectric Ceramics

Aurivillius-type structure compounds are considered good candidates for piezoelectric materials at high temperature, due to their high ferro-paraelectric phase transition temperature. Despite this fact, very few papers have been published on the study of piezoelectric properties at the expected working temperatures. An iterative automatic method has been used in this work to characterize the piezoelectric, electromechanical, and elastic properties at radial resonance of thin ceramic disks with composition (SrBi/sub 2/Nb/sub 2/O/sub 9/)/sub 0.35/(Bi/sub 3/TiNbO/sub 9/)/sub 0.65/[SBN/BTN 35/65], from room temperature up to the ferro-paraelectric phase transition. Ceramics were prepared by sintering or by recrystallization after hot-pressing of mechanically activated precursors. By this new method, ceramics with controlled texture and microstructure are obtained. The influence of the processing route in the properties of the ceramics, over the whole temperature range of piezoelectric activity, is discussed. Values of d/sub 31/=2.1 pC/N and k/sub p/=2.9% at 500/spl deg/C are achieved.

Temperature dependence of piezoelectric, elastic and dielectric coefficients at radial resonance of piezoceramics with an Aurivillius-type structure

Improvement by recrystallisation of Aurivillius-type structure piezoceramics from mechanically activated precursors

This paper presents the design and fabrication of a light deflector made from textured polycrystalline antimony sulfoiodide (SbSI) obtained by gradient freezing during the rapid quenching from the liquid state. The piezoelectric and electrostriction parameters of the textured polycrystalline SbSI are evaluated from the reflection measurements. First time the electrostrictive constant of this material (4.6(1) × 10−13 m2/V2) is reported.

Using of textured polycrystalline SbSI in actuators

The 〈001〉-textured 36Pb(In1/2Nb1/2)O3–30Pb(Mg1/3Nb2/3)O3–34PbTiO3 (36PIN–30PMN–34PT) ceramics were successfully prepared by the templated grain growth method using BaTiO3 (BT) templates with an average edge length of 10 µm and a thickness of about 0.5 µm. The highest Lotgering factor of 95% has been achieved for the textured ceramics with 5 wt% BT templates sintered at 1240 °C. The Curie temperature (TC) and dielectric constant (er) of the textured 36PIN–30PMN–34PT ceramics were 225 °C and 2850, respectively. The piezoelectric constant d33 of the textured samples was 780 pC/N and almost 2 times higher than that of random 36PIN–30PMN–34PT samples. The planar mode electromechanical coupling coefficient kp was 59% for the textured samples. Unipolar strain-field measurements for the textured ceramics exhibited 0.34% strain at 4 kV/mm.

Templated grain growth and piezoelectric properties of 〈001〉-textured PIN–PMN–PT ceramics

Processing, Microstructure and Properties of Grain-Oriented Ferroelectric Ceramics

Properties of ferroelectric ceramics are dependent on crystallites, grain boundaries and pores as well as grain-orientation, secondary-phase and composite structure. Such microstructural parameters have large effects on the electric, dielectric, piezoelectric and mechanical properties of piezoelectric ceramics.1,2)

T. Yamamoto

Papers

Processing, Microstructure and Properties of Grain-Oriented Ferroelectric Ceramics

Effects of Miorostructure Control on Ferroelectric Ceramics