Piezoelectric Textures

Piezoelectric materials have a variety of commercial applications, and a large number of such materials are known. To examine such materials in thin-film form, highly textured crystalline thin films are likely to be needed, so microstructure control is therefore an issue. Screening approaches should be straightforward. 

Ma S, Fuh JYH, Zhang YF, Lu L (2010) Synthesis of anisotropic lead titanate powders for templated grain growth of textured piezoelectric ceramics. Surf Rev Lett 17 159-164... 

Messing GL, Trolier-McKinstry S, Sabolsky EM, Duran C, Kwon S, Brahmaroutu B et al (2004) Templated grain growth of textured piezoelectric ceramics. Crit Rev Solid State Mater Sci 29 45-96... 

Kimura T, Yi Y, Sakurai F (2010) Mechanisms of texture development in lead-free piezoelectric ceramics with perovskite stmcture made by the templated grain growth process. Materials 3 4965-4978... 

Riehter T, Schuh C, Moos R, Suvaci E (2008) Single erystal growth and texturing of lead-based piezoelectric ceramics via templated grain growth process. Funet Mater Lett 1 127-132... 

Wider analyses of utilizing the advantages of textured materials for piezoelectric applications have been provided recently by Messing et al. [49] and Kimura [50] these will be discussed in more detail later in the chapter. 

Seabaugh, M.M., Cheney, G.L., Hasinska, K., Azad, A.M., Sabolsky, E.M., Swartz, S.L., and Dawson, W.J. (2004) Development of a templated grain growth system for texturing piezoelectric ceramics. /. IntAl. Mater Syst. Struct.,... 

Li, J.Y. 2000. The effective electroelastic moduli of textured piezoelectric poly crystalline... 

Many routes for obtaining template particles are known using molten salt synthesis, hydrothermal synthesis, sol—gel processing, as well as hybrid, multistep methods. The TGG method has been widely used for the development and texturing of piezoelectric ceramics [44]. One of the reasons for this widespread use is the cost consideration, since TGG enables the relatively inexpensive fabrication of textured ceramics with single crystal-Uke properties. However, our present discussion pivots around the mechanical properties. 

The tabular ST particles were synthesized by a two-step molten salt process using KCl as a flux. The ST platelets served as templates. Figure 4.59 shows by XRD the random and textured PMN-32.5PT (3 wt% excess PbO, 3 vol% ST) ceramics sintered at 1150 °C for 10 h. The two major peaks in the templated PMN-32.5PT ceramic were (100) and (200), which indicates the high degree of texmring. In the textured XRD, a reflection of the (100) remained, indicating that the texturing did not entirely reach completion. The piezoelectric behavior of the ST and BT6 (i.e.. 

BaTiOa) textured samples and that of a randomly-oriented sample are compared in Fig. 4.60. Textured PMN-32.5PT with 5 vol% ST and no excess PbO showed a maximum strain level of 0.3 % in an electric field of 40 kV/cm, which is approximately twice the strain response of a random ceramic in the same field. Since this material is used for piezoelectric purposes, Fig. 4.60 shows the strain as a function of the electric field. Due to the fine size of the template particles, it was possible to obtain textured ceramics without the use of excess PbO and without extensive matrix grain growth. 

Wood GO, Moyer ES (1991) A review and comparison of adsorption isotherm equations used to correlate and predict organic vapor cartridge capacities. Am Ind Hyg Assoc J 52 235-242 Yanagitani T, Kiuchi M, Matsukawa M, Watanabe Y (2007) Characteristics of pure-shear mode BAW resonators consisting of (1120) textured ZnO films. IEEE Trans Ultrason Eerroelectr Freq Control 54 1680-1686 Ye ZG (ed) (2008) Handbook of advanced dielectric piezoelectric and ferroelectric mater synthesis characterization and applications. Woodhead, Cambridge... 

Both, piezoelectric and pyroelectric behavior is possible only in ferroelectric ceramics, or in otherwise polar materials that are deposited as textured thin films. 

Bunn CW, Alcock TC (1945) The texture of polyethylene. Trans Faraday Soc 41 317-325 Cardoso VF, Minas G, Lanceros-Mendez S (2012) Multilayer spin-coating deposition of poly (vinylidene fluoride) films for controlling thickness and piezoelectric response. Sens Actuators A Phys 192 76-80... 

The chapter begins with an overview of elastic anisotropy in crystalline materials. Anisotropy of elastic properties in materials with cubic symmetry, as well as other classes of material symmetry, are described first. Also included here are tabulated values of typical elastic properties for a variety of useful crystals. Examples of stress measurements in anisotropic thin films of different crystallographic orientation and texture by recourse to x-ray diffraction measurements are then considered. Next, the evolution of internal stress as a consequence of epitaxial mismatch in thin films and periodic multilayers is discussed. Attention is then directed to deformation of anisotropic film-substrate systems where connections among film stress, mismatch strain and substrate curvature are presented. A Stoney-type formula is derived for an anisotropic thin film on an isotropic substrate. Anisotropic curvature due to mismatch strain induced by a piezoelectric film on a substrate is also analyzed. 

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