Studies on the growth, optical, thermal and dielectric aspects of a proton transfer complex – Dimethyl amino pyridinium 4-nitrophenolate 4-nitrophenol (DMAPNP) crystals for non-linear optical applications

Single crystals of dimethyl amino pyridinium 4-nitrophenolate 4-nitrophenol (DMAPNP) were grown by slow evaporation solution growth technique using acetone as solvent at pH 3.26 at constant temperature (30 °C). FT–IR and FT–Raman spectral studies were performed for analyzing and assigning the vibrations and to identify the functional groups. The optical transparency window in the visible and near IR (420–1400 nm) regions was found to be good for non-linear optical applications. Thermogravimetric analysis and differential thermal analysis showed that the compound decomposes beyond 250 °C. The dielectric studies were performed. The relative second harmonic efficiency of the compound is found to be 15 times greater than that of KDP. The laser induced surface damage threshold for the grown crystal was measured as 2.24 GW/cm2 with Nd:YAG laser assembly.