Structure, crystal growth and characterization of piperazinium bis(4-nitrobenzoate) dihydrate crystal for nonlinear optics and optical limiting applications

Abstract

A novel third order nonlinear optical crystal Piperazinium bis(4-nitrobenzoate) dihydrate (PNBA) was grown by slow evaporation method. Crystal structure was determined by single crystal X-ray diffraction analysis and the crystal belongs to triclinic system with centrosymmetric space group. The functional groups of the grown crystal have been identified by FTIR spectroscopic analysis. Optical property of the crystal was characterized by UV–Vis–NIR spectral studies. The crystal is transparent in the entire visible region with a lower cut off wavelength of 355 nm. Thermal and dielectric studies were carried out to study the thermal stability and dielectric behaviour respectively. The PNBA crystal belongs to soft material category is confirmed by Vickers's microhardness study. The solid state parameters such as valence electron, plasma energy, Penn gap and Fermi energy were evaluated theoretically for the PNBA using the empirical relation. The estimated values are used to calculate the electronic polarizability. The third order nonlinear optical(NLO) properties of the crystal have been investigated by Z scan technique. The PNBA crystal exhibits negative nonlinear refractive index.