Journal of Materials Physics and Chemistry, 2013, Vol. 1, No. 1, 4-8 Available online at http://pubs.sciepub.com/jmpc/1/1/2 © Science and Education Publishing DOI:10.12691/jmpc-1-1-2 Growth, Optical, Mechanical, Dielectric and Photoconductivity Properties of L-Proline Succinate NLO Single Crystal P. Balamurugaraj 1,2 , S. Suresh 3,* , P. Koteeswari 4 , P. Mani 4 1 Department of Physics, Bharathiar University, Coimbatore, India 2 Department of Physics, M adha Institute of Engineering & Technology, Chennai, India 3 Department of Physics, Loyola College, Chennai, India 4 Department of Physics, Hindustan Institute of Technology and Science, Chennai, India *Corresponding author: sureshsagadevan@yahoo.co.in Received December 17, 2012; Revised January 29, 2013; Accepted February 28, 2013 Abstract Single crystals of L-Proline Succinate (LPS) were grown by slow evaporation technique. Single crystal X-ray diffraction analysis reveals that the crystal belongs to monoclinic crystal system. The optical transmission study reveals the transparency of the crystal in the entire visible region and the cut off wave length has been found to be 210nm. The optical band gap is found to be 5.90eV. The transmittance of L-Proline succinate crystal has been used to calculate the refractive index (n), the extinction coefficient (K) and the real (ε r ) and imaginary (ε i ) components of the dielectric constant. Mechanical strength of the grown crystal was analyzed using Vickers microhardness tester. Nonlinear optical property of the crystal was confirmed by Kurtz Perry powder technique. Dielectric constant measurements were carried out at different temperatures. Some fundamental data such as valence electron plasma energy, Penn gap, Fermi energy and electronic polarizability of the grown crystal have been estimated. Photoconductivity measurements carried out on the grown crystal reveal the negative photoconducting nature. Keywords: solution growth, single crystal XRD, optical transmission, SHG, dielectric constant, photoconductivity studies 1. Introduction Most of the nonlinear optical materials are currently used in the fabrication of passive and active photonic devices [1,2]. Nonlinear optical processes provide the key functions of frequency conversion and optical switching [3]. These applications depend upon the various properties of the materials, such as transparency, birefringence, refractive index, dielectric constant, therma l, photochemical and chemical stability. Organic nonlinear materials are attracting a great deal of attention, as they have large optical susceptibilities, inherent ultra fast response times and high optical thresholds for laser power as compared with inorganic materials [4]. Although the crystal growing technology for these materials is highly developed and their nonlinear optical susceptibilities are sufficient for most of the current photonic applications, they have features that are less than desirable. Hence, new nonlinear optical materials are needed to extend the range of photonic applications. For any device fabrication in the electronic industry pure and defect less single crystals are needed. In the present work, we have grown the L-Proline succinate single crystal by slow evaporation technique. The grown crystal was characterized using the studies of single crystal XRD, FTIR, UV-VIS-NIR spectral analysis, microhardness and NLO test. Dielectric constant measurements were also carried out at different frequencies and temperatures. Some fundamental data such as valence electron plasma energy, Penn gap, Fermi energy and electronic polarizability of the grown crystal were calculated. Photoconductivity measurements also carried out on the grown crystal reveal the negative photoconducting nature. 2. Experimental Procedure Single crystals of LPS were grown from L-Proline and succinic acid taken in equimolar ratio in aqueous solution by slow evaporation method. The solution was stirred continuously using a magnetic stirrer. The prepared solution was filtered and kept undisturbed at room temperature. Tiny seed crystals with good transparency were obtained due to the spontaneous nucleation. Among them, defect free seed crystal was suspended in the mother solution, which was allowed to evaporate at room temperature. Large size single crystals were obtained due to collection of monomers at the seed crystal sites from the mother solution after the nucleation process was completed. Figure 1 shows as-grown crystals of LPS.