Formation and properties of L-arginine acetate single crystals doped with hydrochloric acid

Abstract

L-Arginine acetate (LAA) single crystals belonging to the amino acid group are reported to have promising NLO properties. In the present study, to improve further the characteristics of LAA crystals, HCl acid was incorporated into the crystal matrix as a dopant. Single crystals of pure and HCl doped LAA (a total of five) were grown successfully by using the slow evaporation technique. The grown crystals were confirmed chemically and structurally by performing X-ray diffraction (single crystal and powder), CHNS elemental, energy dispersive X-ray spectral and Fourier transform infrared spectral analyses. The crystals are found to be thermally stable up to 204 o C.The UV-Vis spectral analysis shows that these crystals have wide transparency range in the entire visible region. Second harmonic generation (SHG) measurement shows the NLO property. Microhardness measurement indicates that the grown crystals come under soft material category. Dielectric measurements were carried out at various temperatures ranging from 40- 140 ⁰C and with various frequencies such as 1 , 10 and 100 kHz by the parallel plate capacitor method. The AC activation energies were also determined. The temperature and frequency dependences of dielectric parameters observed indicate a normal dielectric behavior for all the five crystals grown in the present study.