Investigating optical, mechanical and thermal properties of pristine glycine LiNO ₃ and doped samples

The slow evaporation method was employed to grow 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 the powder XRD technique. The functional groups of the samples were determined by recording Fourier transform infrared spectroscopy (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 are 300[Formula: see text]nm, because wavelengths around 300[Formula: see text]nm are relevant for certain nonlinear optical processes. The band gap for NaNO 3 doping concentration is 6.07[Formula: see text]eV at 20[Formula: see text]mol% and 5.84[Formula: see text]eV at 60 mol%. The energy band gap for KNO 3 doping concentration is 6.21[Formula: see text]eV at 20[Formula: see text]mol% and 5.88 eV at 60 mol%. The thermal gravimetric analysis (TGA) confirmed that up to [Formula: see text]C, the formed crystals remain stable. Mechanical hardness was tested on high-quality crystals using a Vickers micro hardness tester for varied applied loads ranging from 1[Formula: see text]gm to 10[Formula: see text]gm. The hardness of doped NaNO 3 and KNO 3 crystals is higher than that of pure glycine lithium nitrate.