Influence of Isoelectric pH on the Growth Linear and Nonlinear Optical and Dielectric Properties of l -Threonine Single Crystals

Single crystals of l -threonine have been grown from aqueous solutions of different pH values. The crystal grown from the solution of isoelectric pH (PI) was found to have the best linear and nonlinear optical properties. The optical quality of l -threonine was improved greatly in the case of the crystal grown at PI. The morphology of the title crystal has been discussed in detail. The crystalline powder SHG efficiency of l -threonine crystals grown at PI was found to be 1.2 times that of KDP. Capacitance and dielectric loss measurements were also carried out, and the dielectric constant was calculated at room temperature in the frequency range 100 Hz−5 MHz. The dielectric constant of the crystalline sample remains constant for the entire frequency range studied.