Experimental and theoretical studies on physicochemical properties of l-leucine nitrate—a probable nonlinear optical material

• Published in: Journal of crystal growth 2012-10, Vol.356, p.4-9
• Main Authors: Adhikari, Soma, Kar, Tanusree
• Format: Article
• Language: English
• Subjects: A1. Characterization; A1. Crystal Morphology; A1. X-ray diffraction; A2. Growth from solutions; A2. Single crystal growth; Amino acids; Computational efficiency; Computing time; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Diffraction; Electron states; Energy gap; Exact sciences and technology; Growth from solutions; Materials science; Methods of crystal growth; physics of crystal growth; Methods of electronic structure calculations; Nonlinearity; Optical properties; Organic compounds; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Thermal analysis
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2012.07.008

An amino acid salt l-leucine nitrate (LN) has been synthesized and single crystals were grown by the controlled evaporation of the aqueous solution at constant temperature (30±0.01)°C. The structural and physicochemical properties of the grown crystals were characterized by X-ray powder diffraction and thermal analysis. The optical transmission spectra and second harmonic generation (SHG) were investigated to study its linear and nonlinear optical properties. SHG efficiency is comparable to that of KDP. The dipole moment, polarizability, first order hyperpolarizability and the HOMO–LUMO energy gap of LN were calculated at the framework of Hartree–Fock (HF) and density functional theory (DFT) to confirm the suitability of the crystal for nonlinear optical applications. First hyperpolarizability was found to be 9.4 times of that of urea. ► Nonlinear optical crystal l-leucine nitrate was grown from its aqueous solution. ► Second harmonic efficiency of l-leucine nitrate is comparable to that of KDP. ► TG–DTA studies show that the compound is stable up to its melting point at 180.5°C. ► Crystal of l-leucine nitrate is transparent over the entire UV–vis–NIR region. ► First hyperpolarizability of l-leucine nitrate was found to be 9.4 times of that of urea.