The slow evaporation method was employed to growth high-quality single crystals of pure glycine lithium nitrate and doped with NaNO 3 and KNO 3 at room temperature. To determine the diffraction planes and crystal structure, the produced crystals were exposed to powder XRD technique. The functional groups of the samples were determined by recording FTIR spectra. Analyses of the grown samples' ultraviolet (UV)-visible spectrum characteristics were conducted. It was found that for nonlinear applications, the cutoff wavelength and optical transparency required to be 300 nm, because wavelength around 300nm can relevant for certain nonlinear optical processes. The band gap for NaNO3 doping concentration is 6.07eV at 20 mol % and 5.84 eV at 60 mol %. The energy band gap for KNO 3 doping concentration is 6.21eV at 20 mol % and 5.88 eV at 60 mol %. The thermal gravimetric analysis (TGA) confirmed up to 200°C, the formed crystals remain stable. Mechanical hardness was tested on high quality crystals using Vickers micro hardness tester for varied applied loads ranging from 1 gm to 10 gm. The hardness of doped NaNO3 and KNO 3 crystals are higher than that of pure Glycine Lithium Nitrate.
Agrawal et al. (Thu,) studied this question.