International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064 Impact Factor (2012): 3.358 Volume 3 Issue 7, July 2014 www.ijsr.net Licensed Under Creative Commons Attribution CC BY Mechanical Properties of L-Lysine Doped Triglycine Sulfate (TGS) Single Crystals A. T. Ravichandran 1 , A. Judith Jayarani 2 1, 2 PG & Research Department of Physics, National College (Autonomous), Tiruchirappalli-620 001, Tamilnadu, India Abstract: Single Crystals of L-Lysine doped Triglycine Sulfate (TGS) were grown by conventional method. The grown crystals were characterized by single crystal XRD, Powder XRD, FTIR, UV-Vis Spectroscopy and Microhardness. The single crystal and powder XRD was to study the morphology and structure of the grown crystal. The presence of functional group of the materials was qualitatively estimated by FTIR. The optical nature of the crystal was studied by UV-Vis spectroscopy. Mechanical properties were determined by Microhardness studies. The results were discussed. Keywords: TGS, conventional method, optical transmittance, mechanical properties 1. Introduction Triglycine Single Crystals are well known for ferroelectric material. It many potential applications in the field of optoelectronics especially in Infrared detectors, optical transmitters, etc. It has second order phase transition at Curie temperature (49ºC). Ferroelectric materials are polar and possess spontaneous polarization below Curie temperature. TGS has some disadvantages such that it is depolarized by thermal, mechanical and electrical means. Several dopants were added to reduce these types of difficulty to increase the property of the crystal for practical applications. It undergoes the second order phase transition at Curie temperature from ferroelectric to paraelectric [1]. It belongs to the monoclinic system. Many authors have investigated the effect of doping various amino acids like Alanine, Valine, Sacrosine, Tyrosine, etc., on TGS [2, 3]. The space group transform from non-centrosymmetric P 21 in the ferroelectric phase to centrosymmetric P 21/m in the paraelectric phase [1]. In this present work, we report the repercussion of L-Lysine in Triglycine Sulfate (TGS) single crystals. The method e used for the growth of L-Lysine doped TGS was Conventional method which can also be called as slow evaporation solution growth method. The structural studies were made on the grown crystal by single crystal XRD. The powder XRD confirms the crystallinity of the grown crystal. The presence of functional groups confirm by Fourier Transform Infrared Spectroscopy. The mechanical property was estimated by microhardness studies. The optical transmittance was determined by UV-Vis spectroscopy. 2. Experimental work AR grade of Glycine and sulfuric acid were taken for the preparation of the solution 3:1 molar ratio respectively and dissolved in 100ml of de-ionized water. L-Lysine of 8mol% was taken as dopant and added with the saturated solution of TGS. The following reaction taken place: 3 (CH 2 NH 2 COOH)+H 2 SO 4 +xHO 2 CCH(NH 2 )(CH 2 ) 4 NH 2 (CH 2 NH 2 COOH) 3 ·H2SO4·xHO 2 CCH(NH 2 )(CH 2 ) 4 NH 2 The prepared solution was stirred from 8-12 hrs to attain homogeneous solution and it was maintained at 50 ºC to avoid oxidation throughout the preparation of the solution. Then, it was filtered by Whatmann filter paper to reduce the impurity of the solution in undisturbed condition by controlled evaporation. After 2 weeks, nucleation was taken place and the seed crystals were formed. The transparent good quality crystals were select to grow bulk single crystals for optical applications. After 20days later, bulk single crystals were harvest. The grown crystals were shown in fig.1 Figure 1 3. Characterization 3.1 Single Crystal X-ray Diffraction The Single crystal XRD analysis was taken in the Bruker Single crystal X-ray diffractometer with Mo Kα radiation to identify crystal structure and lattice parameters of the grown crystals. 3.2 Powder X-ray Diffraction The powder XRD pattern was recorded by the Reich Sceifert Instrument. The scan time was set as 2min and the angle range from 10°-70°. The recorded pattern is used to analysis the nature of the crystal. Paper ID: 02015140 2323