ISSN: 2277-9655 [Surname* et al., Vol.(Iss.): Month, Year] Impact Factor: 4.116 IC™ Value: 3.00 CODEN: IJESS7 http: // www.ijesrt.com© International Journal of Engineering Sciences & Research Technology [820] IJESRT INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY GROWTH, STRUCTURAL AND MECHANICAL STUDIES OF THIOUREA PHTHALIC ACID (TPA) SINGLE CRYSTALS BY X-RAY POWDER DIFFRACTION AND VICKER’S MICROHARDNESS TESTING M. Suresh Kumar *1 , S. Krishnan 2 , G.V. Vijayaraghavan 3 1 Department of Physics, AMET University, Kanathur 603112, Chennai, India 2 Department of Physics, RKM Vivekananda College, Chennai600004 , India 3 Department of Physics, B. S. Abdur Rahman Crescent University, Chennai 600048, India DOI: 10.5281/zenodo.834548 ABSTRACT Good quality Thiourea Phthalic acid (TPA) single crystals were grown by slow evaporation solution growth technique at room temperature. X-Ray powder diffraction and Mechanical characterizations of slow evaporation grown single crystals of Thiourea-Phthalic acid (TPA) are analyzed in this article. Mechanical properties such as Vicker’s microhardness number, work hardening index, standard hardness value, Yield strength, fracture toughness, brittleness index, and elastic Stiffness constant values are determined using Vicker’s microhardness tester. KEYWORDS: X-Ray Powder diffraction, Yield strength and Stiffness constant. I. INTRODUCTION Organic materials can exhibit higher nonlinear optical efficiencies due to their large electro optic coefficient and higher optical susceptibilities [1]. Crystals of such materials are used in Optoelectronic applications[2-4]. The study of growth, XRD and Microhardness characterizations of Thiourea Phthalic acid single crystals were analysed and reported in this article. The sample crystals were grown by slow evaporation method. The sample crystals of TPA were undergone structural and mechanical studies by using X-Ray powder diffractometer and Vicker’s Microhardness Tester. The hardness of a crystal is generally defined as its resistance to structural breakdown under applied force or stress. Mechanical properties such as Vicker’s microhardness number, work hardening index, standard hardness value, Yield strength, fracture toughness, brittleness index, and elastic Stiffness constant values give valuable information on the physical strength and deformation characteristics of a material[5]. The chemical forces in a crystal resist the motion of dislocations as it involves the displacements of atoms. This hardness is the intrinsic hardness of a crystal. The hardness properties are associated to the structure of the crystal material and hardness studies are carried out to understand about the plasticity of the crystal[6]. Microhardness studies on various crystals using Vicker’s indentor have been reported by many researchers[7-8]. So in this study, the various hardness parameters were determined for TPA crystal using Vicker’s microhardness tester. II. EXPERIMENTAL PROCEDURE Crystal Growth Slow evaporation solution growth technique was used to grow TPA crystals. The saturated solution of a mixture of Thiourea and Phthalic acid in the stoichiometric ratio of 1:1 was prepared with doubly distilled water. The solution was stirred constantly for about 5 hours using a magnetic stirrer. After that the solution was filtered and kept at room temperature (about 30 ο C). The solution was permitted to evaporate the water slowly into the atmosphere. After 3 weeks, TPA crystals were obtained from the mother solution. The collected crystals were recrystallaised to get good quality TPA single crystals.