Ferroelectric applications

Optoelectronic and Ferroelectric Applications 389 3.1 Light Emitting Diodes (LED)... 

Crosslinked LC elastomers (Figure 19d) are very promising for piezoelectric and ferroelectric applications, and also as non-linear optic materials. The first synthetic step to such materials is the preparation of usual side chain or combined LC copolymers doped with a small part of side chains containing a polymerizable >C=C< double bond at the end (Figure 23 shows a particular example of a crosslinkable LC polymer64). The copolymer can be further photocrosslinked, giving an elastic polymer film which reveals... 

The electrical characterization of polar media is crucial to investigate their suitability for ferroelectric memories, piezo- or pyroelectric devices and many other ferroelectric applications (see Chapter 3). Optical characterization of polar media is fundamental to investigate their ser-vicability for electro-optic devices or applications in the field of nonlinear optics (see Chapter 4). Additionally there are intentions to characterize polar media with a combination of both, electrical and optical methods, such as to understand ferroelectric phenomena that are influenced by the action of light. 

The above data show that mixing a polymer with a plasticizer has only marginal influence on volume resistivity of material. But still plasticizers are used in many applications of polymers in conductive and ferroelectric applications. ... 

As is the case in many fields, for example, microelectronics, catalysis, and medidne, much interest has developed in understanding the role of nanodimensions in influencing and ideally optimizing properties. In this chapter, attention is focused on the impact of nanoscale dimensions on the properties of electrically conductive electroceramics and the implications that this may have on applications. This is particularly relevant since electroceramics, by their nature, are dominated by boundaries (grain boundaries, electrode interfaces, surfaces, etc.), with the notable exception of epitaxial thin films, which are optimized for dielectric and ferroelectric applications but are beyond the scope of this chapter [5]. Some boundaries are detrimental to... 

Amino acids are readily available in high enantiomeric excess and have probably been the most used type of chiral precnrsor for the preparation of chiral liquid ciystals and chiral dopants (especially for ferroelectric applications). Two particularly interesting applications of amino acids e.g., 132) in the generation of chiral materials for ferroelectric liquid crystal mixtures (see Chapter 6) are shown in Schemes 31 and 32. 

Gedanken and coworkers [64] sonochemically synthesized LaFeOs nanocrys-talline material with high purity and good homogeneity. It was obtained with lower processing temperatures and shorter annealing times. The obtained nanoferrite powder is expected to be used in applications for functional ceramics (sensors, solid oxide fuel cells (SOFCs), electrodes, or even magnetic and ferroelectric applications). 

For some ferroelectric applications, polymer sheet of 1-2 mm thickness is required. Commercially this can be produced by extruding molten polymer through a die of the appropriate cross-sectional shape and size. The hot extrudate can be led over or through pairs of cooling rollers or into a cooling liquid before it is cut into individual sheets or wound into a roll. 

Ferroelectric Liquid Crystals Principles, Properties and Applications (PMade ph a Gordon and Breach)... 

Piezoelectric and Electrostrictive Device Applications. Devices made from ferroelectric materials utilizing their piezoelectric or electrostrictive properties range from gas igniters to ultrasonic cleaners (or welders) (72). 

J. W. Goodby and co-workers. Ferroelectric Eiquid Cystals Principles, Properties, and Applications, Gordon and Breach Pubhshers, Philadelphia, Pa., 1991. 

Many ceramic applications are high value and small volume, so energy expenditure is high. Ferroelectric magnets, electronic substrates, electrooptics, abrasives such as silicon carbide and diamond, are examples. Diamond is found naturally, and made synthetically by the General Electric Company at high pressure and temperature. Synthetic diamonds for abrasives require less energy to make than the value in Table 4 nevertheless, the market is carefully divided between natural and synthetic diamonds. 

Since niobates and tantalates belong to the octahedral ferroelectric family, fluorine-oxygen substitution has a particular importance in managing ferroelectric properties. Thus, the variation in the Curie temperature of such compounds with the fluorine-oxygen substitution rate depends strongly on the crystalline network, the ferroelectric type and the mutual orientation of the spontaneous polarization vector, metal displacement direction and covalent bond orientation [47]. Hence, complex tantalum and niobium fluoride compounds seem to have potential also as new materials for modem electronic and optical applications. 

Yu. Xu, Ferroelectric materials and their applications, Elsevier Science Publishers B.V., North-Holland, Amsterdam, 1991. 

A.I. Agulyansky, V.T. Kalinnikov, Actual problems of preparation and application of ferroelectric and piezoelectric materials. Abstracts of III Vses. Confer. Moscow NIITEChlM 1987 p. 15 (in Russian). 

M.E. Lines, A.M. Glass Principals and application of ferroelectrics and related materials, Clarendon Press, Oxford, 1977. 

A.P. Leonov, S.Yu. Stephanovich, Preparation and application of ferroelectric materials, Nauka, Moscow, 1984, p. 21 (in Russian). 

WangTT, Herbert JM, Glass AM (1987) The applications of ferroelectric polymers. Blackie, Glasgow... 

Five-membered sulfur-containing heterocycles are important synthetic intermediates and have found a variety of applications in medical, agricultural, and material chemistry. Looking for potential candidates for ferroelectric display applications. Seed s group investigated the preparation of liquid crystals... 

Important ferroelectric materials are those with piezoelectric characteristics. They are crystalline ceramics that exhibit expansion along one crystal axis and contraction along another when subjected to an electrical field. Conversely, compression generates an electrical voltage across the material. These materials have a large number of industrial applications. 

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