Growth and characterization of dl-Alanine — A new NLO material from the amino acid family

Single crystals of dl-Alanine (C₃H₇NO₂), one among the rare amino acid racemates crystallizing in a non-centrosymmetric space group and a new NLO material, were grown from aqueous solution by slow evaporation method. They were characterized by single crystal X-ray diffraction. Fourier transform infrared spectroscopy (FTIR) showed the presence of the different functional groups. The thermal stability and decomposition of the sample was studied by thermal analysis (TGA/DTA). The optical transparency was studied by UV–Vis–NIR spectral analysis. The above experimental results showed that dl-Alanine is stable up to 280 °C and transparent in the region of 220 nm–1100 nm. The second harmonic generation (SHG) efficiency was determined using Kurtz and Perry method and found to be 1.7 times higher than that of standard KDP.