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Chapter V Dielectric Study of ……
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Chapter V
Dielectric Study of Pure and L-histidine, L-threonine and
5.1 Introduction
DL-methionine Doped KDP Crystals
Dielectric study is important part of materials characterizations,
because it does not only throw light on the materials behavior under the
influence of applied electric field but also its applications. In general, for any
molecules will have two possibilities when influenced by an external field,
1. Molecules may have permanent dipole moments which may be aligned in
an external field.
2. The distances between ions or atoms may be influenced by external field.
However, the polarization in atoms or molecules is induced by an
external field by displacing electrons with respect to the corresponding nuclei.
The electric properties of molecules are generally characterized by three
quantities,
(i) Polarizability due to electronic displacement within atoms or ions.
(ii) Polarizability due to atomic or ionic displacement within the molecules.
(changes in bond angles and inter-atomic distances)
(iii) A permanent dipole moment.
Notwithstanding, the discussion becomes more interesting when solid
material is considered for dielectric study for both static and alternating fields.
This may lead to some interesting phenomena like piezoelectric effect,
pyroelectric effect and ferroelectric effect in certain crystals. This has brought
novel applications of various materials in science and technology.
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