Third-order nonlinear optical treatment of (Ni and Fe)-doped zeolitic imidazolate framework-67: Synthesize and characterization

A simple chemical reaction was applied for fast preparation of pure zeolitic imidazolate framework-67 (ZIF-67) and doped with Ni or Fe ions. The distinctive bands appeared in FT-IR spectrum of each samples confirmed the successful synthesis of ZIF-67 samples. The surface morphology and microstructure of prepared pure ZIF-67 were evaluated by TEM and SEM techniques. A rhombic dodecahedron skeleton with smooth surface was shown for the ZIF-67. The SEM images of ZIF-67 doped with Ni or Fe indicated a polyhedral shaped nanostructures smaller than 300 nm. Considering the XRD pattern, the crystallinity index of samples was calculated. The large optical nonlinearities of Ni, and Fe doping ZIF-67 were characterized using a 532 nm wavelength laser source. All synthesized samples showed the nonlinear refractive index and the nonlinear absorption coefficient in the order of 10−8 cm2/W and 10−5 cm/W, respectively. The crystallinity index and polarizability of (Ni, Fe)-ZIF-67 were increased in comparison with ZIF-67. The bigger ionic radius causes to have more electrons and raises polarization. The large two-photon absorption (TPA) and self-defocusing effect of Fe-ZIF-67 made it suitable for related applications in optical limiting devices.