International Journal of ChemTech Research CODEN (USA): IJCRGG ISSN : 0974-4290 Vol.6, No.6, pp 3237-3240, Aug-Sep 2014 ICMCT-2014 [10 th – 12 th March 2014] International Conference on Materials and Characterization Techniques Optical and Dielectric Characterization of a new Non linear Optical Urea Sodium Chloride single crystal by slow evaporation technique E. Ilango 1 *, K. Shankar 1 , V. Chithambaram 2 , R. Rajasekaran 3 , 1 Research and Development Centre, Bharathiar University, Coimbatore, India 2 Research Centre Physics, Dhanalakshmi College of Engineering, Chennai, India 3 Department of Physics, Govt. Arts College, Thiruvannamalai, India *Corres. author: ilangonithish75@gmail.com.com Abstract: Single crystals of Urea Sodium Chloride a novel semi organic non linear optical crystal has been synthesized using slow evaporation technique at room temperature. The lattice parameters for the grown crystals were determined using single crystal XRD. The functional groups of the grown crystal were found by using Fourier Transform Infrared spectroscopy. The UV cut-off wavelength is found to be at 210 nm. TG / DTA studies show thermal properties. The dielectric constant and dielectric loss of the crystal were measured as a function of frequency and temperatures. The second harmonic generations was confirmed by the emission of green radiation. Keywords: Growth from solution, Optical properties, Dielectric constant. Introduction In recent years many significant achievements have been occurred in the field of nonlinear optics because of semi organic materials. Nonlinear optical (NLO) materials plays a vital role in the field of optical computing, optical communication, optical switching, electro-optic shutters, optical modulations, optical logic, frequency shifting, optical data storage for developing technologies in telecommunication, signal processing, optical parallel information processing, laser fusion reaction and medical diagnostics [1-7]. In the present study, urea is combined with sodium chloride to form a new semi organic nonlinear optical material and its properties like optical and dielectrics studies. 1. Experiment The starting material was synthesized by taking Urea (AR grade) and sodium chloride (AR grade) in 1:1 molar ratio and it was dissolved in millipore water of resistivity 18.2 MΩ cm. The solutions were thoroughly mixed for about 12 hours using a magnetic stirrer to ensure homogeneous concentration over entire volume of the solution. The solution was left undisturbed for slow evaporation. After 25 days, optically good quality single crystal USC of size 11mm x 9mm x 5mm were grown and are shown in Fig.1.