Growth and characterization of semi organic nonlinear optical L-Valine Ferric Chloride single crystal by solution growth technique P. Geetha a , S. Krishnan b , R.K. Natarajan a , V. Chithambaram a, * a Research Center Physics, Dhanalakshmi College of Engineering, Chennai, India b Department of Physics, B.S Abdur Rahman University, Vandalur, Chennai, India article info Article history: Received 14 July 2014 Received in revised form 1 November 2014 Accepted 24 November 2014 Available online 9 December 2014 Keywords: Crystal growth Optical materials Nonlinear optics Thermal studies abstract L-Valine Ferric Chloride single crystal is a new semi organic nonlinear optical material. It has been grown from a mixture of aqueous solutions of L-Valine and Ferric Chloride by slow evaporation solution growth technique at room temperature for the first time. Single crystal XRD analysis revealed that the crystal system belongs to Cubic P with cell parameters are a ¼ 24.38 Å, b ¼ 24.38 Å, c ¼ 24.38 Å and volume is 14,485 Å 3 . The UV spectrum shows existence of wide transparency window suitable for optoelectronic applications. Thermal stability and melting temperature of the as grown crystal was identified from TG- DTA analysis. Spectroscopic studies have been carried out for analyzing the presence of functional groups, thermal stability and phase transition of the grown crystal. The dielectric loss and the dielectric constant of the crystals were measured as a function of frequency. Photoluminescence study was carried out for grown crystals and the maximum emission occurs has good optical transmission in the entire visible region. Second harmonic generation (SHG) conversion efficiency has been estimated. © 2014 Elsevier B.V. All rights reserved. 1. Introduction In recent years, many significant achievements have been occurred in the field of nonlinear optics because of the develop- ment of new nonlinear optical (NLO) crystals of both organic and inorganic types. Single crystals made from the organic and inor- ganic compounds play an important role in nonlinear optical device fabrication due to their versatile property such as high second harmonic generation efficiency, fast response and high mechanical strength over the organic counterparts. Organic NLO materials exhibiting large optical nonlinearity have wide application in telecommunication, optical information processing and high opti- cal disk data storage [1,2]. The materials possessing large second order nonlinear susceptibility with favourable in thermal and me- chanical stability are intensively used in many device applications [3]. Hence, there is a great demand to synthesize and grow new organic NLO materials and their single crystals. The advantages of organic materials over inorganic compounds comprise high second order nonlinear optical susceptibility through high molecular Polarizability, fast response time, lower dielectric constant and refractive index. In the last decades, many researchers have tried to find varieties of new NLO materials for laser applications [4]. The main drawback in organic nonlinear optical materials is low me- chanical strength and poor physico-chemical stability. To overcome these drawbacks an attempt has been made to grow semi-organic nonlinear optical crystals (combination of organic acids and inor- ganic salts and metal-organic coordination compounds) which makes the material to be nonlinear and good mechanical strength [5,6]. Amino acid of L-Valine has been exploited for the formation of salts with inorganic acids. As a result, good NLO material such as L- Valine hydro bromide, L-Valinium succinate and L-Valine hydro- chloride [7] were already reported. In the present work the title compound was successfully syn- thesized by combining L-Valine and Ferric chloride in equimolar ratio. The single crystals have been grown by solution growth slow evaporation technique using water as the solvent. To have a full understanding about the structure and its NLO properties for the grown crystals single crystal XRD structure analyses, Powder XRD, FTIR, UVeVis absorption, Thermal analyses (TG/DTA), and SHG measurements were also been carried out. Dielectric and Photo- luminescence studies are also taken for the grown crystal. The following studies have been analysed the crystal structure and the physical properties of the as grown crystal. * Corresponding author. E-mail address: chithambaramv@gmail.com (V. Chithambaram). Contents lists available at ScienceDirect Current Applied Physics journal homepage: www.elsevier.com/locate/cap http://dx.doi.org/10.1016/j.cap.2014.11.014 1567-1739/© 2014 Elsevier B.V. All rights reserved. Current Applied Physics 15 (2015) 201e207