Crystal growth, structural, third-order nonlinear optical susceptibility of Hexakis (Urea-kO) Zinc (II) Dinitrate single crystal for photonic and optoelectronics devices

Single crystals of hexakis (urea-kO) zinc (II) dinitrate ([Zn (CO(NH₂)₂)₆] (NO₃)₂)-HUZDN) were successfully synthesized and grown at ambient temperature via a controlled slow evaporation growth process. The structural characteristics of the crystal were characterized using single-crystal X-ray diffraction study. High-resolution XRD (HR-XRD) was performed to assess the crystal’s structural perfection. The elemental composition of the HUZDN crystals was verified through CHN analysis. Fourier Transform Infrared (FTIR) spectroscopy was utilized to identify the various vibrational modes present in the crystal. Optical measurements, including absorption and transmittance spectra, confirmed the crystal’s transparency in the visible region. Mechanical strength was evaluated through microhardness testing on various crystallographic planes, revealing a load-dependent hardness behavior. Surface features such as etch pits were examined under a high-resolution optical microscope, and the corresponding etch pit density was measured. Dielectric properties, including relative permittivity and dielectric loss, were measured across a range of frequencies and temperatures along three principal crystallographic orientations. The refractive index (n₂) of the cultivated crystal was also determined. Additionally, the laser damage threshold was assessed utilizing a Nd:YAG laser, and the third-order nonlinear optical susceptibility was measured using the same laser source.