Download (4Mb) - Etheses - Saurashtra University

Chapter V Dielectric Study of ……
-
In the present author’s laboratory, the dielectric property of many crystals
were studied earlier, for example, organic molecular crystals 4-(2-
hydroxyphenylamino)–pent–3-en-2-one [23], calcium pyrophosphate crystals
[24], Mn +2 [25] and Cu +2 [26] doped calcium tartrate crystals, pure and mixed
iron manganese levo tartrate crystals [27] and zinc tartrate crystals [28].
It is important to study the effect of irradiation on dielectric properties.
The dielectric properties of barium strontium borate, a NLO crystal, was
investigated by Ishwar Bhat et al [29], before and after irradiation by 8 MeV
electrons as well as silver ions of 120 MeV. It was found that there was an
increase in the dielectric constant due to swift heavy ion irradiation as well as
due to electron irradiation. The effect of swift heavy ions on the dielectric
properties of doped and undoped ammonium dihydrogen phosphate (ADP)
crystals was also investigated by Ishwar Bhat et al [30]. The increase in
dielectric constant was found to be dependent on dopants in the crystals and
electronic energy loss in the crystals. The effect of swift heavy ion (SHI)
irradiation of doped and undoped ADP crystals has been studied by Bhat et al
[31]. The change in the dielectric constant was noted after the irradiation and
the increase in dielectric constant was found to be dependent on dopants in
the crystals and electronic energy losses in crystals.
Ananda Kumari and Chandramani [32] have studied dielectric properties
of Au + doped/undoped KDP crystals containing KI/NaI with varying frequency
at room temperature. They have found that the dielectric constant decreases
with increase in frequency of applied field. Ambujam et al [33] have measured
the dielectric properties of γ-glycine single crystals (an organic NLO material).
204