Exploration on transport process of optically active third-order nonlinear disodium succinate hexahydrate (β phase) single crystals encompassing Self-focusing nature

摘要

Disodium succinate hexahydrate (Na_2C_4H_4O_4.6H_2O) (DSSH) ((3 phase), an optically active third-order nonlinear single crystal encompassing self-focusing nature, has been harvested by the solvent evaporation technique at ambient temperature. Single-crystal XRD study authenticates DSSH (β phase) has cen-trosymmetric monoclinic crystal structure. To measure the optical transmit-tance, the sample of around 1 mm thickness has been exploited in the wavelength region between 200 and 900 nm and the cutoff wavelength substantiated as 296 nm. The optical transparency of the sample in the visible region is quite excellent and the theoretical calculation of optical constant, for instance reflectance, refractive index, electrical, optical conductivities, and electrical susceptibility, was computed. Moreover, the single-crystal quality, purity, and structural defect were corroborated using Urbach energy. The refractive index value is lower compared to the KDP crystal and the harvested crystal is most suited for solar thermal device applications. The optical conductivity for lower photon energies is seem to be minimum; on the other hand, it increases with increasing photon energies, conversely, the electrical conductivity decreases with a rise in photon energy. The activation energy is intended to be 0.0259 eV for frequency 2 M Hz and the lower value of activation energy divulges that the crystal retains lesser defects. In addition, AC and DC conductivity were measured at various temperatures using dielectric study data at different frequencies, and the results were deliberated in detail. The variation of the power law exponent 's' with temperature discloses that the AC conductivity is controlled by the Correlated Barrier Hopping (CBH) conduction mechanism. Photoacoustic analysis is employed to determine the thermal diffusivity and the value for disodium succinate hexahydrate is 0.2 times higher than KDP and formulates that the grown crystal to be a noteworthy candidate for nonlinear optical applications.