Characteristics and quality of grown potassium thiourea iodide crystal for second harmonic generation

A desirable quality bulk single crystal of a novel organometalic nonlinear optical material of potassium thiourea iodide measuring 20 × 10 × 6 mm³ have been grown successfully from solution by slow evaporation method. The solubility curve of this material has been determined in double distilled water which is the most suitable solvent. The diffraction curve by HRXRD method corresponds to (531) plane of the tetragonal crystal. This paper reports vacancy type of point defects in the grown crystal by high resolution XRD method. Entrapped impurities during the crystal growth process are also reported. A stable- small and nearly same value of dielectric loss at four different temperatures in the high frequency range indicates comparatively better quality assessment of the grown crystal. Powder XRD and a.c. conductivity measurements are also carried out. The results of dielectric studies at four different temperatures indicate that the grown crystal is a promising optical material for photo induced second harmonic generation in laser physics.