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Chapter V Dielectric Study of ……
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Figure: 5.13 Plots of dielectric loss versus frequency for pure and DL-methionine doped
KDP crystals.
Figure (5.11) exhibits the variation dielectric loss (tan ) with frequency for L-
histidine doped KDP crystals. From the figure one can notice that as the
frequency increases the dielectric loss decreases. Also, the dielectric loss
decreases as the amount of doping increases in the crystals. The high
amount of doping makes the crystals less lossy. The similar nature was
observed for L-threonine and DL-methionine doped KDP crystals, which has
been shown in figures (5.12) and (5.13), respectively.
The value a.c. resistivity is calculated by using the expression,
ac
A
(5.22)
2fCd
Where, d is the thickness of the pellet, C is the capacitance, f is the frequency
and A is the area of the pellet.
Figure (5.14) shows the plots of a.c. resistivity versus frequency of
applied field for pure and L-histidine doped KDP crystals. It can be noticed
that as the frequency increases the a.c. resistivity decreases. It can also be
noticed that the value of a.c. resistivity is the least for pure KDP crystals and
progressively increases on increasing the doping concentration. The similar
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