Investigation on growth, growth kinetics and characterization of L-valine L-valinium perchlorate monohydrate single crystal

Abstract

The ultimate focus of this paper is on nucleation and growth kinetics, structural and dielectric behavior of l-valine l-valinium perchlorate monohydrate (LVPM) single crystal. LVPM single crystals were grown by conventional slow evaporation technique at room temperature. Salient nucleation parameters, essential for the growth of good quality crystal were estimated with the help of solubility curve and Classical Nucleation Theory (CNT). Single Crystal X-ray Diffraction (SC-XRD) analysis reveals that the synthesized crystal (LVPM) possesses monoclinic structure with lattice parameters as a = 11.227 Å, b = 5.82 Å, c = 13.08 Å, α = γ = 90º and β = 91º. The above results were also confirmed by powder XRD study. The structure of the grown crystal was analyzed by using SHELXT-2014/7 program. It is found that grown crystal belongs to non-centrosymmetric space group P21. All the functional groups and also carboxyl and amino functional groups of LVPM crystal were identified and confirmed by Fourier Transform Infra-red (FTIR) spectroscopy. The molecular structure of the grown crystal and in particular, the presence of amino group was discussed by using 1H and 13C Nuclear Magnetic Resonance (NMR) spectra. The low values of dielectric constant and dielectric loss at higher frequencies indicate that the grown crystal enhances the Second Harmonic Generation (SHG) efficiency. The activation energy of the grown crystal was estimated as 0.1433 eV from AC conductivity study. Kurtz and Perry powder experiment was performed to explore the Nonlinear Optical (NLO) properties of LVPM and its SHG efficiency was found 1.5 times of KDP (1.5’ KDP). The grown material was also found possessing SHG efficiency nearly five times higher than most of the l-arginine compounds. Since the grown material belongs to non-centrosymmetric group and exhibits improved structural, NLO and dielectric behavior, the material will be useful in optoelectronic devices, fiber optic communication, computing, optical switching, image reconstruction, optical storage technology, 3D-images, etc.