Crystal growth and characterization of γ-glycine grown from potassium fluoride for photonic applications

Single crystals of γ-glycine, an organic nonlinear optical material have been synthesized in the presence of potassium fluoride (KF) by slow evaporation technique at ambient temperature. The size of the grown crystal is up to the dimension of 12 mm × 10 mm × 8 mm. The γ-phase was confirmed by single crystal X-ray diffraction, powder XRD and the FTIR analysis. Optical absorption spectrum reveals that the grown crystal has good optical transparency in the entire visible region with an energy band gap of 5.09 eV, which is an essential requirement for a nonlinear optical crystal. Thermal stability of the grown γ-glycine crystal was determined using the thermo gravimetric and differential thermal analyses. The NLO activity of γ-glycine was confirmed by the Kurtz powder technique using Nd:YAG laser and the grown crystal exhibits high relative conversion efficiency when compared to potassium dihydrogen phosphate (KDP).

Single crystals of γ-glycine, an organic nonlinear optical material have been synthesized in the presence of potassium fluoride (KF) by slow evaporation technique at room temperature. From single crystal XRD measurements, γ-glycine has been found to crystallize in the hexagonal structure, space group P31 with cell parameters a = b = 7.0397(5) Å and c = 5.4922(4) Å. Second-harmonic generation (SHG) on powder samples has been measured using Kurtz and Perry technique, which indicated that its SHG efficiency is about 3 times than that of standard inorganic KDP sample.Figure optionsDownload as PowerPoint slideHighlights
► Transparent single crystals of γ-glycine grown from potassium fluoride by using slow evaporation technique at room temperature have not been reported.
► The γ-phase was confirmed by single crystal X-ray diffraction study.
► The calculated energy gap is 5.09 eV from optical absorption studies.
► The SHG efficiency of the titled compound was estimated as 3 times higher than that of KDP.