EDTA effect on Copper Sulphate Penta Hydrate-A NLO Material

Abstract

Ethylene Diamine Tetra Acetic acid (EDTA) doped copper sulphate penta hydrate were grown for five different parent-dopant combinations using slow solvent evaporation method at 300 K and good optical quality crystals were harvested for minimum dopant ratio. The single crystal X-ray diffraction studies reveal the crystal system of the doped crystal to be triclinic with cell parameters a = 5.963(5) Å; b = 6.124(2)Å;  c=10.740(2)Å and volume v =365(2)Å3;  showing that the incorporation of the dopant has not altered the structure of the parent material. The sharp well defined Bragg’s peaks observed in the powder XRD pattern confirm the crystalline nature of the as grown CuEDTA complex. The powder X-ray diffraction analysis reveals the quality and purity of the grown crystal. The modes of vibrations of different molecular groups present in grown crystal were identified and the complex formation with copper was confirmed by FT-IR technique. The optical transparency with lower cut off wave length ~ 190 nm was studied by Ultra Violet (UV)-Visible-Near IR spectral analysis. The thermal stability of the crystals was investigated by Thermo Gravimetric and Differential Thermal Analyses (TGA & DTA). The melting point of the grown crystal was confirmed by Differential Scanning Calorimetric (DSC) analysis.  The endothermic peak at 134.50ºC in DSC graph indicates the melting point of the grown crystal. Vickers micro hardness study and the linear graph drawn show the mechanical properties. The surface textures like hillocks and pits were seen by chemical etching using optical microscope. The effect of the influence of dopant on the surface morphology of CuEDTA crystal faces are analyzed by scanning electron microscope (SEM). The Second Harmonic Generation (SHG) efficiency of the grown CuEDTA crystal has been tested by the Kurtz-Perry powder technique using Nd:YAG laser and was found to be 0.32 times that of KDP. The amount of EDTA (124 g/ml) present in the grown crystal was determined quantitatively by colorimetric estimation method.