Synthesis, crystal structure, optical and third order nonlinear optical properties of phosphoric acid pyridine-1-ium-2-carboxylate

A semi-organic nonlinear optical material phosphoric acid pyridine-1-ium-2-carboxylate (PAPC) crystal has been synthesized and grown. Vibrational spectral analysis and NMR spectral analysis has been carried out. Mechanical studies on the grown crystal has been performed which disclose the material belongs to soft materials category. The thermal behaviour of the grown crystal has been investigated by thermogravimetric and differential thermal analysis. UV–Visible spectral analysis has been carried out which reveals that the grown crystal is transparent in the entire visible region with the lower cut-off wavelength of 298 nm and the derived optical constant attests the suitability of this material for non-linear optical applications. The third order nonlinearity has been studied by z-scan method and the enhanced third-order nonlinearity shows PAPC is a potential material for device applications. Second harmonic generation efficiency has been studied by Kurtz and Perry powder test and is found as 0.14 times greater than the KDP.