Ammonium Zinc Nickel Sulphate Hexahydrate (AZNSH) crystal, belonging to the Tutton’s salt family, was grown using the conventional slow evaporation solution growth method (SESGM) as well as the Sankaranarayanan–Ramasamy (SR) method to obtain high-quality single crystals. A well-faceted AZNSH single crystal with a diameter of 1.0 cm and a length of 6.5 cm was successfully grown by the SR method using a small seed crystal placed at the bottom of the ampoule(s). The crystal system is monoclinic with the space group as P2 1 /c, and the lattice parameters are a as 6.2412 Å, b as 12.4915 Å, and c as 9.2080 Å and beta as 106.941 o for pure; a as 6.2419 Å, b as 12.4920 Å, and c as 9.2086 Å and beta as 106.952 o for 50 Gy irradiated and a as 6.2424 Å, b as 12.4928 Å, and c as 9.2095 Å and beta as 106.981 o for 50-shock pulsed. The transmittance spectrum exhibits three transmittance windows centred at 340 nm, 510 nm, and 880 nm, along with strong absorption at higher wavelengths. The lower cutoff wavelength occurs for pure AZNSH at 290 nm. The irradiated and shock-pulsed samples show slight shifts in the lower cutoff wavelength to 296 nm and 304 nm, respectively. The Tauc’s plots, presented the band gap values of 4.28 eV, 4.19 eV, and 4.08 eV for the pure, 50 Gy irradiated, and 50 shock-pulsed samples, respectively. The combined values from UV-visible data confirms these band gap values as 4.2758, 4.1891, and 4.0789 eV. Photoluminescence-PL behaviour of the title compound, four emission peaks were observed at 460, 468, 493, and 507 nm, as shown. The peaks at 493 nm and 507 nm exhibited higher intensity than the others. The emission energies corresponding to these wavelengths were calculated as 2.69 eV, 2.64 eV, 2.51 eV, and 2.44 eV, respectively. Thus, the crystal emits three blue and one green light at these wavelengths. The dielectric constant versus frequency plots for pure, 50 Gy irradiated, and 50 shock-pulsed samples are shown as the dielectric constant varies significantly at lower frequencies and responds actively to temperature changes. Dielectric loss as a function of frequency is shown for the same samples, displaying a decrease with increasing frequency. As shown the dark current exceeds the photocurrent in all three sample types, indicating a negative Photoconductivity behaviour. Second-order nonlinear optical (NLO-SHG) efficiencies of the AZNSH samples were measured to be 2.04, 2.05, and 2.08 times that of Potassium Dihydrogen Phosphate (KDP) for the pure, irradiated, and shock-pulsed crystals, respectively. Voltage regulation by diodes was represented increases of 4%, 6%, and 8.5% observed for the pure, 50 Gy irradiated, and 50 shock-pulsed samples, respectively than the normal case. Additionally, the filter influx value for the pure AZNSH crystal was measured at 2.9899 microns. In this study, the measured LDT value for the AZNSH crystal of pure, 50 Gy irradiated, and 50 shock-pulsed samples were 9.88; 9.89; 9.92 GW/cm 2 , which is higher than that reported for many other similar materials. Thermogravimetric analysis (TGA) provides valuable information about the thermal stability and physico-chemical changes in the crystal and Differential Scanning Calorimtery-DSC provides the composite nature of crystal. The high transmittance in the visible range and the wide band gap of the as-grown material demonstrate its suitability for optical, thermal, photonic and opto-electronic applications; the packing density profile that gives the idea of atomic packing of AZNSH.
Sathish et al. (Sun,) studied this question.