Piezoelectric applications

The major piezoelectric applications are sensors (pickups, keyboards, microphones, etc.), electromechanical transducers (actuators, vibrators, etc ), signal devices, and surface acoustic wave devices (resonators, traps, filters, etc ). Typical materials are ZnO, AIN, PbTiOg, LiTaOg, and Pb(Zr.Ti)03 (PZT). 

In pyrroelecttic devices, a chaige is developed across the film in response to heating and such devices may serve as ir-detectors (see Infrared TECHNOLOGY AND RAMAN SPECTROSCOPY). Piezoelectric applications are promising as sound detectors, because for these, a chaige is developed across the film in response to pressure. A review is available (74). 

Lithium tantalate is a single-crystal material that is produced in quantity by the Czochralski method (see Section 3.11) for piezoelectric applications and is therefore readily available. It is stable in a hard vacuum to temperatures that allow outgassing procedures. It is insensitive to humidity. It is widely used where precise measurements are to be made. 

What is the objection to using PZT compositions of the type developed for piezoelectric applications in a pyroelectric infrared detector What are the properties needed and how have they been achieved ... 

Subsequently due to specific chain conformation in crystal unit cell and providing the highest remnant polarization, p phase has attracted more attention than the others in pyro-and piezoelectric applications (J.Jungnickel, 1996). 

PbTi03, for pyroelectric detectors and hydrophones LiTa03, for pyroelectric sensors Pb(Sci/2Tai/2)03, (Bao.6oSro.4o)Ti03, for pyroelectrics Pb(Zri Ti )03, for piezoelectric applications of all types... 

Ferroelectrics are the prime material for piezoelectric applications in ceramic form, due to the discovery of the electrical poling process that aligns the internal polarization of the crystallites within the ceramic, and causes the ceramic to act in similar fashion to a piezoelectric single crystal. Three categories of applications have... 

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. 

Kingon, A.I. and Srinivasan, S. (2005) Lead zirconate titanate thin films directly on copper electrodes for ferroelectric, dielectric and piezoelectric applications. Nat. Mater., 4 (3), 233-237. 

Actuator materials are classified into three categories piezoelectric, elec-trostrictive and phase-change materials. Modified lead zirconate titanate [PZT, Pb(Zr,Ti)03l ceramics are currently the leading materials for piezoelectric applications. The PLZT [(Pb,La)(Zr,Ti)03l 7/62/38 compound is one such composition [31], The strain curve is shown in Figure 4.1.19a (left). When the applied field is small, the induced strain x is nearly proportional to the field E (x = dE, where d is called the piezoelectric constant). As the field becomes larger (i.e. greater than about IkV/cm), however, the strain curve deviates from this linear trend and significant hysteresis is exhibited due to polarization reorientation. This sometimes limits the use of such materials for actuator applications that require non-hysteretic response. 

Relating to the application needs material research and development takes place. Some of the materials used in the piezoelectric applications in early history are not... 

Relatively few applications have utilized the ferroelectric effect in ceramics. Ferroelectric ceramics have been widely employed because of the other properties that they display, however. Their dielectric, piezoelectric, and pyroelectric properties have led to their use in capacitor, actuator and other piezoelectric applications, and infrared detection devices. Again, the most widely used materials are the lead-based ABO perovskite compounds. 

Fukuda, T., Takeda, H., Shimamura, K, Kawanaka, H., Kumatoriya, M., Murakami, S., Sato, J., Sato, M., (1998). "Growth of New Langasite Single Crystals for Piezoelectric Applications" Proceedings of the Eleventh IEEE International Symposium, ISBN 0-7803-4959-8, Montreux, Switzerland, August 1998. 

Shimamura, K., Takeda, H., Kohno, T., Fukuda, T., (1996). "Growth and characterization of lanthanum gallium silicate La3Ga5SiOi4 single crystals for piezoelectric applications" /. Crystal Growth, 163, pp. 388-392. 

ZnO is an electronic and photonic material mainly because of its band gap of 3.37 eV. It has been widely used in near-UV emission, gas sensors, transparent conductors and piezoelectric applications [34-38]. There have been many existing... 

GlauB, B., Steinmann, W., Walter, S., Beckers, M., Seide, G., Gries, T., Roth, G., 2013. Spiim-ability and characteristics of pol3 vinylidene fluoride (PVDF)-based bicomponent fibers with a carbon nanotube (CNT) modified polypropylene core for piezoelectric applications. Materials 6 (7), 2642-2661. 

In Proceedings of powerMEMS 2004, Kyoto, pp 187-190 Bhrendt N (2010) Tailored processing methods for cellular polycarbonate and polyetherimide films - new potentials for electret and piezoelectric applications. IEEE Trans Dielectr Electr Insul 17 (4) 1113... 

Two-inch LGS single crystals were grown via the vertical Bridgman method assisted by the accelerated crucible rotation technique (ACRT) along [0001] (Z-axis), [211 0] (X-axis) and [0111] (54°-rotated Y-axis) for piezoelectric applications. 

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