A novel centrosymmetric crystal structure of Bis 15-Crown-5 ether cadmium tri potassium thiocyanate [2(C1_0H20O₅) k][Cd (SCN)₃] single crystal investigated by Z-scan technique

Nonlinear optical single crystal of bis 15-crown-5-ether (C₁₀H₂₀O₅) cadmium tri potassium thiocyanate was grown by slow evaporation technique. Parameters like solubility and growth rate play a vital role on the growth of thiocyanate family crystal. Furthermore, single crystal X-ray diffraction patterns provide detailed information about the lattice dimensions, crystal symmetry, bond length and bond angle, etc. This study reveals that title structure is monoclinic with a space group of P2_1/n. The lower cut-off wavelength of the sample was found to be 261 nm with optical band gap of 2.33 eV, which was calculated from UV-vis-NIR spectroscopy by Tauc's relation. The grown crystal functional groups were identified and compared with FT-IR and micro-Raman spectroscopy. Additionally, dielectric, thermal, and mechanical properties of as-grown crystals are analyzed by the dielectric constant (ε_r) with dielectric loss (tanδ), decomposition temperature, hardness (HV), and Mayer's index (n) number. Third-order nonlinear optical coefficients (χ³) are determined by using Z-scan studies, and they play a curial role in the field of photonic device fabrication. (author)