Growth and characterization studies of a new NLO single crystal potassium l-asparaginate

Abstract

Potassium l-asparaginate (PLA) is a new semiorganic NLO material of amino acid family. In this work, we have grown PLA single crystal by slow evaporation method. The lattice parameters were calculated from single crystal XRD data. XRD analysis yielded a space group of P21 with lattice parameters a=10.470Å, b=8.839Å, c=12.808Å, α=β=90°≠γ, volume=1185.30Å3. Solubility studies were made at different temperatures with various solvents. The solubility was found to be 17g in 100ml of water at room temperature. The functional groups present in the grown sample were identified from the vibrational frequencies of the recorded FTIR spectrum. UV–vis-NIR spectrum of PLA crystal shows the cut off wavelength of the crystal to be at 230nm. The second harmonic generation efficiency of PLA single crystal estimated using Kurtz and Perry method. The nature of variation of dielectric constant (ɛr) and dielectric loss (D) with frequency at different temperatures were investigated. The AC conductivity measurements done on PLA reveal that PLA crystal has a sharp electrical conductivity with an increase of temperature.