Structural, Spectroscopic, Thermal studies of Pure and DL-Methionine Doped ADP Crystals

The growth of Nonlinear Optical crystals retains great number of attention nowadays. Ammonium Dihydrogen Phosphate (ADP) is an important NLO material used for electro-optical applications and LASER material for Nd: YAG and Nd: YLF etc. Amino acids due to their properties like molecular chirality and zwitter ionic structure attract many researchers to dope them in ADP for the improvement of its properties. The Pure and 0.1wt% DL-Methionine doped ADP crystals were grown using slow solvent evaporation technique at room temperature. The Powder XRD shows single phase nature of doped crystal with slight variation in unit cell parameters. The interaction of DL-Methionine with functional groups of ADP crystal was studied using FT-IR spectroscopy. The TGA curve of pure ADP sample indicates that it remain stable upto 200 oC and then decompose slowly, while the doped sample slowly decomposes right from beginning of the analysis. The DTA curves exhibits endothermic peaks at 209 oC and 212 oC for pure and doped sample, respectively.