Studies on synthesis,growth and characterization of a novel third order nonlinear optical 4-Dimethylaminopyridinium p-Toluenesulfonate single crystal

Good quality single crystals of 4-Dimethylaminopyridinium p-Toluenesulfonate (4DMAPPTS) possessing third order nonlinearity were grown by slow evaporation solution technique (SEST). Single crystal X-ray diffraction analysis reveals that 4DMAPPTS belongs to monoclinic crystal system with centrosymmetric space group P2₁/n. FT-IR spectral studies were carried out to identify the functional groups present in 4DMAPPTS. NMR spectral study confirms the molecular structure of the grown crystal. Dielectric measurements were made over a wide range of frequencies for different temperatures. The grown crystal was subjected to Vickers microhardness test to study the mechanical property. The etching studies reveal the growth pattern and dislocations present in the grown title crystal. The important optical parameters such as absorption coefficient, extinction coefficient, refractive index and optical band gap were estimated from UV–Visible spectral analysis. The negative third order nonlinear optical parameters like refractive index (n₂), absorption coefficient (β) and susceptibility (χ⁽³⁾) were estimated by Z-scan studies.