Synthesis, growth and investigation of an efficient nonlinear optical single crystal: glycine sodium fluoride

Glycine sodium fluoride (GSF) single crystals were grown in aqueous solution at room temperature through the slow evaporation method. The grown crystal is confirmed to be hexagonal by X-ray single crystal diffraction analysis. By analyzing the FTIR spectrum, the functional groups present in the grown crystal were determined. The optical band gap energy Eg is calculated to be 5.81 eV and the crystal is transparent in the visible range with a lower cut-off wavelength of 243 nm. Using a Nd:YAG laser with a fundamental wavelength of 1064 nm, the second harmonic generation was established by the Kurtz–Perry technique. The measurements of nonlinear absorption coefficient, nonlinear refractive index and third-order nonlinear susceptibility were carried out in a Z-scan experiment to determine the third-order NLO behaviour of GSF crystal. The crystal dielectric properties were measured from 50 Hz to 5 MHz at different temperatures. The research into the crystal photo conductivity shows that it is really a positive photo conductor. SEM analysis was used to investigate the surface morphology. Sodium metal has been incorporated into GSF crystal, as shown by energy dispersive X-ray analysis. There was a red emission peak at 648 nm in the photoluminescence spectrum. In order to determine the thermal parameters of a GSF crystal, thermogravimetric and differential thermal analyses were used.