Investigations on growth and characterization of glycine admixture sodium molybdate crystals for nonlinear optical applications

Single crystals of semi-organic nonlinear optical material tris-glycine sodium molybdate were grown by slow evaporation technique from aqueous solution at room temperature. Good optical quality crystals with dimensions of 2.3 × 1 × 0.5 cm3 were obtained. Single crystal X-ray diffraction was used to measure the unit cell parameters and affirmed the crystal structure. Powder X-ray diffraction revealed that the crystallinity of the crystals grown. Fourier transform infrared spectra confirmed the complex formation of glycine and sodium molybdate. Ultra violet absorption studies indicate that the crystals were transparent in the entire visible range. Direct optical band gap and indirect optical band gap values of the grown crystals were calculated from the Tauc plot. Vickers microhardness test was performed to understand the mechanical strength of the crystals. Thermal stability and melting point of the grown crystal was identified from thermo gravimetric analysis and differential thermal analysis. The surface morphology of the grown crystals was studied using scanning electron microscope analysis. Chemical composition and purity of the crystal was corroborated by energy dispersive X-ray analysis. The nonlinear optical property of the crystal was measured by Kurtz and Perry powder technique using Nd:YAG laser operating at 1064 nm.