Semiorganic nonlinear optical tris(thiourea) cadmium sulphate (TTCS) single crystals were grown by slow evaporation method. The crystal system, cell parameter of the grown crystal, was identified by powder X-ray diffraction study. The self-focusing -scan technique has been employed to observe the third-order nonlinear optical property of the grown crystal. The mechanical property of the grown crystal was examined by using Vicker’s microhardness test. Chemical etching studies were made on the TTCS crystal using water as an etchant. The dark current and photocurrent properties of the crystal were estimated by using photoconductivity study. The dielectric constant of grown crystal was studied in different temperature by varying applied frequencies. 1. Introduction The semiorganic nonlinear optical (NLO) materials have a significant impact on laser technology, optical communication, and are applied in optical storage technologies in recent years [1, 2]. The organic materials have large NLO coefficient when compared to inorganic materials, but their usage is impeded due to their poor mechanical strength, low thermal stability, and low laser damage threshold [3]. This organic molecular salt exhibits interesting NLO properties because of its strong Coulomb interactions between charged molecules [4]. The inorganic materials have excellent mechanical and thermal properties but possess relatively modest optical nonlinearities, due to lack of extended π-electron delocalization [5]. Both the high nonlinear optical efficiency and stable materials are the interest of the future technological advancements. The semiorganic material offers great materials for second- and third-order nonlinear optical applications. The solution growth technique is the efficient way to produce good quality semiorganic NLO crystals [6]. One such semiorganic material is the metal complex of thiourea. The thiourea molecule is an interesting inorganic matrix modifier because of its large dipole moment. It has good ability to form an extensive network of hydrogen bond and has the coordination capacity to form different phases of metal-thiourea complexes [7, 8]. In our study, thiourea a typical polar molecule was selected to combine with cadmium sulphate and its results are summarized. 2. Experimental Work The semiorganic nonlinear optical compound tris(thiourea) cadmium sulphate (TTCS) was synthesized by direct chemical reaction. The calculated amount of AR grade thiourea (3？mol%) and cadmium sulphate (1？mol%) was dissolved in deionized water. The mixtures of the reactants were stirred well
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