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Chapter III CHN Analysis, FT IR …..
presence of extra phase can be detected by powder XRD. Podder et al [37]
have investigated lattice distortion in urea and KCl doped KDP crystals, and
found that the structures of the doped crystals were slightly distorted
compared to pure KDP crystal. This might be attributed to strains on the
lattice by the absorption of urea and KCl. Pritula et al [38] studied the effect of
urea doping concentration on unit cell parameters of KDP by powder XRD. To
determine the lattice parameters of KDP crystals more precisely, the
parameter c depending on the concentration of urea in solution has been
measured by the Bond method. The lattice parameter c (∆c = 1.4 X 10 3 )
essentially increased with the concentration of 0.2M/2.0M of urea to the
solution. At urea concentration exceeding 0.2M, the observed lattice
parameter variation was insignificant. The author have also pointed out that
the behavior of the lattice parameter a was less sensitive to the change in
urea concentration in the solution. Kumaresan et al [39] studied the powder
XRD patterns of various organic dye (Amaranth, Rhodamine B and Methyl
Orange) doped KDP crystals. Dyes distorted the crystal structure of doped
KDP slightly. This might be due to the strain on the lattice by absorption or
substitution of dyes. Peaks observed in the doped KDP crystals were
correlated well with those observed in individual parent compound with slight
shift in the Bragg angle.
Recently, several authors [15,18,40-42] have reported powder XRD
studies of amino acid doped KDP crystals. All the workers have reported the
single phase nature after doping and shift in the peak positions with change in
unit cell parameters. Gunasekaran and Ramkumar [15] obtained the unit cell
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