K. Vivekanandan et al., RAMAN AND FT-IR SPECTROSCOPIC CHARACTERIZATION OF FLUX-GROWN KTIOPO4 AND KRBTIOPO4 NONLINEAR-OPTICAL CRYSTALS, Materials chemistry and physics, 49(3), 1997, pp. 204-210
Single crystals of KTiOPO4 (KTP) and K0.5Rb0.5TiOPO4 (KRbTP) have been
grown using the slow fooling flux method. Laser Raman and FT-IR spect
ra were recorded on these crystals in the frequency range 20-4000 cm(-
1). The observed Raman infrared bands are assigned to vibrations of th
e PO4 tetrahedra, TiO6 octahedra, combination and overtone bands of PO
4 groups, OH- ion modes and external modes. The vibrational assignment
s of PO4 and TiO6 vibrations have been approximated in terms of T-d an
d O-h, symmetry species, respectively. Changes observed in the Raman a
nd FT-IR spectra of KRbTiOPO4 crystals are discussed due to the presen
ce of Rb ion. The vibrational data indicate that the tungsten (W6+) im
purity is incorporated into the tungsten based flux grown KTP crystal
at Ti4+ sites. Further,it has been observed that the presence of OH- d
efects is dependent on the growth conditions, i.e. type of flux used a
nd the presence of impurity.