A new class semi-organic nonlinear optical materials: Mono(4-sulfo benzene aminium) tri nickel(II) bis(dihydrogen phosphate) for photonic applications

This article is discussing the growth of a new class semi-organic nonlinear crystal (4-sulfo benzene aminium) tri nickel(II) bis(dihydrogen phosphate) (4-STNBDHP) grown by slow evaporation solution growth technique at ambient temperature. The purity of the crystal was achieved by recrystallization and the size of the crystal is 3 × 3 × 7 mm3. It was harvested over the period of 85 days. The solubility of the 4-STNBDHP crystal is done at different temperatures from 30 °C to 80 °C in steps of 10 °C. Lattice parameters, obtained from the result of single crystal X-ray diffraction study, indicate that the grown crystal is an orthorhombic crystal. FTIR spectral investigations indicated the formation of bonds like N–H⋯O, O⋯Ni–O and Ni–O–P and these bonds are arising because of doping. The UV–visible spectrum demonstrates that the grown crystals are transparent and an absorption peak at 768 nm indicates the presence of Ni2+ ions. TGA/DTA investigations were made to study the decomposition of the title compound. Nonlinear optical (NLO) efficiency of the crystal was tested through second harmonic generation efficiency test. Photoluminescence study shows the green light emission. The microhardness analysis confirms that the grown crystal belongs to the soft material. From tis study, the mechanical properties such as stiffness constant (C11), yield strength (δy), hardness (Hv), and hardening coefficient (n) were calculated. The dielectric constant (ε), dielectric loss (ε′), imaginary dielectric constant (ε″), AC conductivity (σac) and Cole-Cole graphs were plotted. From this study, it is concluded that the 4-STNBDHP shows higher conduction at a higher temperature and at low frequency. The elemental analysis was carried out by energy dispersive X-ray analysis and it confirms the presence of the different elements in the 4-STNBDHP crystal. Keywords: Crystal growth, NMR, EDAX, Optical properties, AC conductivity property