Growth, structural, and spectral characterizations of potassium and ammonium zinc sulfate hydrate single crystals

Abstract

Single crystals of potassium zinc sulfate hydrate and ammonium zinc sulfate hydrate are grown from solution by slow evaporation technique. The crystals were characterized by different instrumental techniques. Powder X-ray diffraction analysis was carried out to detect the crystal structure and proved that the grown crystals are of the desired chemical and structural properties. The calculated lattice constants are in good agreement with the reported data. Thermal analysis was carried out using DTA and TGA to characterize the thermal stability of the grown crystals. The modes of vibration of different functional groups were assigned and reported by the Fourier transform infrared spectral analysis of the grown crystals. The optical properties are measured in the photon energy range of 190–800 nm and the as-grown single crystals show direct-allowed interband transitions, and the corresponding values of direct optical energy gaps are calculated. The refractive index, the real and imaginary parts of the dielectric permittivity, and the extinction coefficient were also calculated as a function of photon energy, and the results were discussed. The dispersion of the refractive index has been analyzed, and the optical parameters have been estimated.