Growth and optically active third-order nonlinear optical material: nicotinic acid as optical limiters

An optically good nonlinear organic material, Nicotinic acid, was grown from slow evaporation (solvent) method. The XRD pattern revealed the monoclinic structure which underwent to centrosymmetric space group. The grown crystal functional groups and well-defined optical efficiencies were determined from FT-IR and UV–Visible spectrum. Various optical properties such as reflectance and extinction coefficient are studied and good crystalline feature with low defect is analyzed from the Urbach energy for the grown crystal. The position of energy band is clearly studied, and the emission spectrum is recorded based on the electron excitation from higher to lower energy levels. The calculated solid-state properties support the enhanced NLO nature of the grown material. The strong mechanical stability and moderate threshold value is determined. The evaluated χ⁽³⁾ from Z-scan studies supports better third-order NLO property when compared with other organic crystals. The OL (optical limiting) behavior shows its limiting threshold to be 3.96 mW/cm² which substantiates its suitability as optical limiters.